diff --git a/knowledge base/1password-cli.md b/knowledge base/1password-cli.md
index 44a81c4..3ad4544 100644
--- a/knowledge base/1password-cli.md	
+++ b/knowledge base/1password-cli.md	
@@ -47,12 +47,13 @@ All the references in the [further readings] section, plus the following:
 
 - [CLI getting started] guide
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [cli getting started]: https://support.1password.com/command-line-getting-started/
 [cli guide]: https://support.1password.com/command-line/
 
-<!-- in-article references -->
+<!-- In-article sections -->
 [further readings]: #further-readings
-
-<!-- internal references -->
-<!-- external references -->
diff --git a/knowledge base/acl.md b/knowledge base/acl.md
index 9b09c2d..c0774f2 100644
--- a/knowledge base/acl.md	
+++ b/knowledge base/acl.md	
@@ -4,7 +4,6 @@
 
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## TL;DR
 
@@ -31,16 +30,11 @@ setfacl -b 'test/declarations.h'
 
 ## Further readings
 
-## Sources
-
-All the references in the [further readings] section, plus the following:
-
 - [Access Control Lists (ACL) in Linux]
 
-<!-- upstream -->
-<!-- in-article references -->
-[further readings]: #further-readings
+<!--
+  References
+  -->
 
-<!-- internal references -->
-<!-- external references -->
+<!-- Others -->
 [access control lists (acl) in linux]: https://www.geeksforgeeks.org/access-control-listsacl-linux/
diff --git a/knowledge base/agg.md b/knowledge base/agg.md
index 77f53f9..6f371a0 100644
--- a/knowledge base/agg.md	
+++ b/knowledge base/agg.md	
@@ -6,7 +6,6 @@ Command-line tool for generating animated GIF files from asciicast files produce
 
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## TL;DR
 
@@ -22,19 +21,9 @@ agg 'path/to/file.cast' 'path/to/file.gif'
 
 - [Asciinema] to record terminal sessions
 
-## Sources
-
-All the references in the [further readings] section, plus the following:
-
 <!--
-  references
+  References
   -->
 
-<!-- upstream -->
-<!-- article sections -->
-[further readings]: #further-readings
-
-<!-- knowledge base -->
+<!-- Knowledge base -->
 [asciinema]: asciinema.md
-
-<!-- others -->
diff --git a/knowledge base/android.md b/knowledge base/android.md
index 426b906..e235ddc 100644
--- a/knowledge base/android.md	
+++ b/knowledge base/android.md	
@@ -69,13 +69,16 @@ All the references in the [further readings] section, plus the following:
 
 - [How to Use ADB and Fastboot on Android]
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [adb]: https://developer.android.com/studio/command-line/adb
 
-<!-- in-article references -->
+<!-- In-article sections -->
 [further readings]: #further-readings
 
-<!-- internal references -->
-<!-- external references -->
+<!-- Others -->
 [how to use adb and fastboot on android]: https://www.makeuseof.com/tag/use-adb-fastboot-android/
 [using adb and fastboot]: https://wiki.lineageos.org/adb_fastboot_guide
diff --git a/knowledge base/ansible.md b/knowledge base/ansible.md
index 99d8214..5716b96 100644
--- a/knowledge base/ansible.md	
+++ b/knowledge base/ansible.md	
@@ -529,7 +529,11 @@ All the references in the [further readings] section, plus the following:
 - [How to recursively set directory and file permissions]
 - [Is it possible to use inline templates?]
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [ansible galaxy user guide]: https://docs.ansible.com/ansible/latest/galaxy/user_guide.html
 [automating helm using ansible]: https://www.ansible.com/blog/automating-helm-using-ansible
 [configuration]: https://docs.ansible.com/ansible/latest/reference_appendices/config.html
@@ -539,13 +543,13 @@ All the references in the [further readings] section, plus the following:
 [templating]: https://docs.ansible.com/ansible/latest/user_guide/playbooks_templating.html
 [tests]: https://docs.ansible.com/ansible/latest/user_guide/playbooks_tests.html
 
-<!-- in-article references -->
+<!-- In-article sections -->
 [further readings]: #further-readings
 
-<!-- internal references -->
+<!-- Files -->
 [templating examples]: ../examples/ansible/templating.yml
 
-<!-- external references -->
+<!-- Others -->
 [check if a list contains an item in ansible]: https://stackoverflow.com/questions/28080145/check-if-a-list-contains-an-item-in-ansible/28084746
 [edit .ini file in other servers using ansible playbook]: https://syslint.com/blog/tutorial/edit-ini-file-in-other-servers-using-ansible-playbook/
 [how to append to lists]: https://blog.crisp.se/2016/10/20/maxwenzin/how-to-append-to-lists-in-ansible
diff --git a/knowledge base/antigen.md b/knowledge base/antigen.md
index b628f29..cfee818 100644
--- a/knowledge base/antigen.md	
+++ b/knowledge base/antigen.md	
@@ -5,7 +5,6 @@
 1. [Troubleshooting](#troubleshooting)
    1. [While loading, a completion fails with error `No such file or directory`.](#while-loading-a-completion-fails-with-error-no-such-file-or-directory)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## Troubleshooting
 
@@ -30,16 +29,10 @@ antigen apply
 - [Github]'s repository
 - Antigen's [Wiki]
 
-## Sources
+<!--
+  References
+  -->
 
-All the references in the [further readings] section, plus the following:
-
-<!-- upstream -->
+<!-- Upstream -->
 [github]: https://github.com/zsh-users/antigen
 [wiki]: https://github.com/zsh-users/antigen/wiki
-
-<!-- in-article references -->
-[further readings]: #further-readings
-
-<!-- internal references -->
-<!-- external references -->
diff --git a/knowledge base/apk.md b/knowledge base/apk.md
index baa3b0b..05b8e7d 100644
--- a/knowledge base/apk.md	
+++ b/knowledge base/apk.md	
@@ -64,10 +64,11 @@ apk info -d 'parallel'
 
 ## Sources
 
-- [10 Alpine Linux apk Command Examples]
+- [10 alpine linux apk command examples]
 
-<!-- upstream -->
-<!-- in-article references -->
-<!-- internal references -->
-<!-- external references -->
+<!--
+  References
+  -->
+
+<!-- Others -->
 [10 alpine linux apk command examples]: https://www.cyberciti.biz/faq/10-alpine-linux-apk-command-examples/
diff --git a/knowledge base/apt-file.md b/knowledge base/apt-file.md
index 80de762..c700ea3 100644
--- a/knowledge base/apt-file.md	
+++ b/knowledge base/apt-file.md	
@@ -24,12 +24,15 @@ All the references in the [further readings] section, plus the following:
 
 - [List of files installed from apt package]
 
-<!-- upstream -->
-<!-- in-article references -->
+<!--
+  References
+  -->
+
+<!-- In-article sections -->
 [further readings]: #further-readings
 
-<!-- internal references -->
+<!-- Knowledge base -->
 [apt]: apt.md
 
-<!-- external references -->
+<!-- Others -->
 [list of files installed from apt package]: https://serverfault.com/questions/96964/list-of-files-installed-from-apt-package#96965
diff --git a/knowledge base/apt.md b/knowledge base/apt.md
index b5e599d..440c3cd 100644
--- a/knowledge base/apt.md	
+++ b/knowledge base/apt.md	
@@ -211,20 +211,24 @@ All the references in the [further readings] section, plus the following:
 - [cheat.sh]
 - [Fix a "Problem with MergeList" or "status file could not be parsed" error]
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [apt configuration]: https://wiki.debian.org/AptConfiguration
 [apt_preferences man page]: https://manpages.debian.org/testing/apt/apt_preferences.5.en.html
 [configuring apt sources]: https://wiki.debian.org/SourcesList
 [unattended upgrades]: https://wiki.debian.org/UnattendedUpgrades
 
-<!-- in-article references -->
+<!-- In-article sections -->
 [further readings]: #further-readings
 
-<!-- internal references -->
+<!-- Knowledge base -->
 [apt-file]: apt-file.md
 [dpkg]: dpkg.md
 [netselect-apt]: netselect-apt.md
 
-<!-- external references -->
+<!-- Others -->
 [cheat.sh]: https://cheat.sh/apt
 [fix a "problem with mergelist" or "status file could not be parsed" error]: https://askubuntu.com/questions/30072/how-do-i-fix-a-problem-with-mergelist-or-status-file-could-not-be-parsed-err#30199
diff --git a/knowledge base/arch linux.md b/knowledge base/arch linux.md
index 8714f40..00bccde 100644
--- a/knowledge base/arch linux.md	
+++ b/knowledge base/arch linux.md	
@@ -20,10 +20,10 @@ git clone https://aur.archlinux.org/jdupes.git \
 - [Suspend and hibernate]
 - [Arch User Repository]
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [arch user repository]: https://wiki.archlinux.org/title/Arch_User_Repository
 [suspend and hibernate]: https://wiki.archlinux.org/title/Power_management/Suspend_and_hibernate
-
-<!-- in-article references -->
-<!-- internal references -->
-<!-- external references -->
diff --git a/knowledge base/armbian.md b/knowledge base/armbian.md
index 5d551eb..b210aa7 100644
--- a/knowledge base/armbian.md	
+++ b/knowledge base/armbian.md	
@@ -7,7 +7,6 @@ Based on Debian.
 
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## TL;DR
 
@@ -16,17 +15,15 @@ Based on Debian.
 - [Website]
 - [Debian] GNU/Linux
 
-## Sources
+<!--
+  References
+  -->
 
-All the references in the [further readings] section, plus the following:
-
-<!-- upstream -->
+<!-- Upstream -->
 [website]: https://www.armbian.com/
 
-<!-- in-article references -->
+<!-- In-article sections -->
 [further readings]: #further-readings
 
-<!-- internal references -->
+<!-- Knowledge base -->
 [debian]: debian.md
-
-<!-- external references -->
diff --git a/knowledge base/asciinema.md b/knowledge base/asciinema.md
index f411a0e..6320842 100644
--- a/knowledge base/asciinema.md	
+++ b/knowledge base/asciinema.md	
@@ -6,7 +6,6 @@ Terminal session recorder.
 
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## TL;DR
 
@@ -38,22 +37,13 @@ asciinema upload 'path/to/file.cast'
 - [Github]
 - [`agg`][agg] to convert cast files into GIFs
 
-## Sources
-
-All the references in the [further readings] section, plus the following:
-
 <!--
-  references
+  References
   -->
 
-<!-- upstream -->
+<!-- Upstream -->
 [github]: https://github.com/asciinema/asciinema
 [website]: https://asciinema.org/
 
-<!-- article sections -->
-[further readings]: #further-readings
-
-<!-- knowledge base -->
+<!-- Knowledge base -->
 [agg]: agg.md
-
-<!-- others -->
diff --git a/knowledge base/asdf.md b/knowledge base/asdf.md
index ff4a42a..034615a 100644
--- a/knowledge base/asdf.md	
+++ b/knowledge base/asdf.md	
@@ -150,13 +150,14 @@ The versions listed in such file can be:
 - [plugins list]
 - [`.tool-versions` example][.tool-versions example]
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [github]: https://github.com/asdf-vm/asdf
 [homepage]: https://asdf-vm.com/
 [plugins list]: https://github.com/asdf-vm/asdf-plugins
 
-<!-- in-article references -->
-<!-- internal references -->
+<!-- Files -->
 [.tool-versions example]: ../examples/.tool-versions
-
-<!-- external references -->
diff --git a/knowledge base/atom.md b/knowledge base/atom.md
index df7c398..a094bd3 100644
--- a/knowledge base/atom.md	
+++ b/knowledge base/atom.md	
@@ -1,5 +1,13 @@
 # Atom
 
+> DEPRECATED
+
+## Table of contents <!-- omit in toc -->
+
+1. [Troubleshooting](#troubleshooting)
+   1. [Zsh terminal icons are not getting displayed in Atom PlatformIO Ide Terminal](#zsh-terminal-icons-are-not-getting-displayed-in-atom-platformio-ide-terminal)
+1. [Further readings](#further-readings)
+
 ## Troubleshooting
 
 ### Zsh terminal icons are not getting displayed in Atom PlatformIO Ide Terminal
@@ -7,8 +15,13 @@
 Change font to `NotoSansMono Nerd Font` in PlatformIO Ide Terminal's settings.  
 See [Why Zsh terminal icons are not getting displayed in Atom PlatformIO Ide Terminal?]
 
-## Sources
+## Further readings
 
 - [Why Zsh terminal icons are not getting displayed in Atom PlatformIO Ide Terminal?]
 
+<!--
+  References
+  -->
+
+<!-- Others -->
 [why zsh terminal icons are not getting displayed in atom platformIO ide terminal?]: https://forum.manjaro.org/t/why-zsh-terminal-icons-are-not-getting-displayed-in-atom-platformIO-ide-terminal/64885/2
diff --git a/knowledge base/authenticate without using sudo.md b/knowledge base/authenticate without using sudo.md
index 2fe3546..d5a017b 100644
--- a/knowledge base/authenticate without using sudo.md	
+++ b/knowledge base/authenticate without using sudo.md	
@@ -1,8 +1,14 @@
 # Authenticate without using sudo
 
+## Table of contents <!-- omit in toc -->
+
+1. [Polkit](#polkit)
+1. [Further readings](#further-readings)
+1. [Sources](#sources)
+
 ## Polkit
 
-Requires [polkit] to be:
+Requires [`polkit`][polkit] to be:
 
 - installed
 - configured to authorize and authenticate the users
@@ -13,12 +19,21 @@ pkexec COMMAND
 
 ## Further readings
 
-- [pkexec]
-
-[pkexec]: pkexec.md
+- [`pkexec`][pkexec]
 
 ## Sources
 
+All the references in the [further readings] section, plus the following:
+
 - [How to get gui sudo password prompt without command line]
 
+<!--
+  References
+  -->
+
+<!-- Knowledge base -->
+[pkexec]: pkexec.md
+[polkit]: polkit.md
+
+<!-- Others -->
 [how to get gui sudo password prompt without command line]: https://askubuntu.com/questions/515292/how-to-get-gui-sudo-password-prompt-without-command-line
diff --git a/knowledge base/awk.md b/knowledge base/awk.md
index 60cd43f..ab9c390 100644
--- a/knowledge base/awk.md	
+++ b/knowledge base/awk.md	
@@ -32,10 +32,11 @@ awk '$2 > 100' sales.txt
 - [Printing the last column of a line in a file]
 - [The essential Bash cheat sheet]
 
-<!-- upstream -->
-<!-- in-article references -->
-<!-- internal references -->
-<!-- external references -->
+<!--
+  References
+  -->
+
+<!-- Others -->
 [print line only if number in third field is greater than x]: https://unix.stackexchange.com/questions/395588/print-line-only-if-number-in-third-field-is-greater-than-x#395593
 [printing the last column of a line in a file]: https://stackoverflow.com/questions/13046167/printing-the-last-column-of-a-line-in-a-file#13046224
 [the essential bash cheat sheet]: https://betterprogramming.pub/the-essential-bash-cheat-sheet-e1c3df06560
diff --git a/knowledge base/aws.md b/knowledge base/aws/cli.md
similarity index 84%
rename from knowledge base/aws.md
rename to knowledge base/aws/cli.md
index 62a2260..5ad96cd 100644
--- a/knowledge base/aws.md	
+++ b/knowledge base/aws/cli.md	
@@ -1,5 +1,11 @@
 # AWS CLI
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Profiles](#profiles)
+1. [Further readings](#further-readings)
+
 ## TL;DR
 
 ```sh
@@ -36,10 +42,15 @@ Default output format [None]: json
 $ export AWS_PROFILE="work"
 ```
 
-## Sources
+## Further readings
 
 - CLI [quickstart]
 - [Configure profiles] in the CLI
 
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [quickstart]: https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-quickstart.html
 [configure profiles]: https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-profiles.html
diff --git a/knowledge base/boinc.md b/knowledge base/boinc.md
index 3df5a49..0d9864c 100644
--- a/knowledge base/boinc.md	
+++ b/knowledge base/boinc.md	
@@ -12,7 +12,6 @@
 1. [Ask for tasks for alternative platforms](#ask-for-tasks-for-alternative-platforms)
 1. [Gotchas](#gotchas)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## TL;DR
 
@@ -151,30 +150,26 @@ In `cc_config.xml`:
 - [boinctui] for a TUI manager
 - [GUI RPC bind to port 31416 failed: 98]
 
-## Sources
+<!--
+  References
+  -->
 
-All the references in the [further readings] section, plus the following:
-
-<!-- upstream -->
+<!-- Upstream -->
+[amd linux drivers]: https://www.amd.com/en/support/linux-drivers
 [boinc manager]: https://boinc.berkeley.edu/wiki/BOINC_Manager
 [client configuration]: https://boinc.berkeley.edu/wiki/Client_configuration
 [controlling boinc remotely]: https://boinc.berkeley.edu/wiki/Controlling_BOINC_remotely
+[installing or uninstalling the amdgpu stack]: https://amdgpu-install.readthedocs.io/en/latest/install-installing.html
 [platforms]: https://boinc.berkeley.edu/trac/wiki/BoincPlatforms
+[radeon™ software for linux® installation]: https://amdgpu-install.readthedocs.io/en/latest/
 [website]: https://boinc.berkeley.edu/
 
-<!-- in-article references -->
-[further readings]: #further-readings
 
-<!-- internal references -->
+<!-- In-article sections -->
 [boinccmd]: boinccmd.md
 
-<!-- external references -->
-[boinctui]: https://www.mankier.com/package/boinc-tui
+<!-- Others -->
 [boinc on arch wiki]: https://wiki.archlinux.org/title/BOINC
-[linux suspend when computer is in use bug]: https://boinc.berkeley.edu/dev/forum_thread.php?id=14019&postid=101146#101146
-
-[amd linux drivers]: https://www.amd.com/en/support/linux-drivers
-[installing or uninstalling the amdgpu stack]: https://amdgpu-install.readthedocs.io/en/latest/install-installing.html
-[radeon™ software for linux® installation]: https://amdgpu-install.readthedocs.io/en/latest/
-
+[boinctui]: https://www.mankier.com/package/boinc-tui
 [gui rpc bind to port 31416 failed: 98]: https://boinc.mundayweb.com/wiki/index.php?title=GUI_RPC_bind_to_port_31416_failed:_98
+[linux suspend when computer is in use bug]: https://boinc.berkeley.edu/dev/forum_thread.php?id=14019&postid=101146#101146
diff --git a/knowledge base/boinccmd.md b/knowledge base/boinccmd.md
index bb10bff..7d41f09 100644
--- a/knowledge base/boinccmd.md	
+++ b/knowledge base/boinccmd.md	
@@ -5,7 +5,6 @@
 1. [TL;DR](#tldr)
 1. [Gotchas](#gotchas)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## TL;DR
 
@@ -69,16 +68,14 @@ boinccmd --set_network_mode 'never' '600'
 ## Further readings
 
 - [Boinccmd tool]
+- [Boinc]
 
-## Sources
+<!--
+  References
+  -->
 
-All the references in the [further readings] section, plus the following:
-
-<!-- upstream -->
+<!-- Upstream -->
 [boinccmd tool]: https://boinc.berkeley.edu/wiki/Boinccmd_tool
 
-<!-- in-article references -->
-[further readings]: #further-readings
-
-<!-- internal references -->
-<!-- external references -->
+<!-- Knowledge base -->
+[boinc]: boinc.md
diff --git a/knowledge base/check the temperature of components.md b/knowledge base/check the temperature of components.md
index aa278fd..e851f67 100644
--- a/knowledge base/check the temperature of components.md	
+++ b/knowledge base/check the temperature of components.md	
@@ -2,18 +2,18 @@
 
 See [lm-sensors], [hddtemp] or [nvme-cli].
 
-## Further readings
-
-- [LM sensors]
-- [Hddtemp]
-- [nvme-cli]
-
 ## Sources
 
 - [How to check CPU temperature on Ubuntu Linux]
 
+<!--
+  References
+  -->
+
+<!-- Knowledge base -->
 [hddtemp]: hddtemp.md
 [lm-sensors]: lm-sensors.md
 [nvme-cli]: nvme-cli.md
 
+<!-- Others -->
 [how to check cpu temperature on ubuntu linux]: https://www.cyberciti.biz/faq/how-to-check-cpu-temperature-on-ubuntu-linux/
diff --git a/knowledge base/combine multiple pdf files.md b/knowledge base/combine multiple pdf files.md
index ae8c4ec..387622f 100644
--- a/knowledge base/combine multiple pdf files.md	
+++ b/knowledge base/combine multiple pdf files.md	
@@ -1,7 +1,10 @@
 # Combine multiple PDF files
 
-## Further readings
+See [`pdftk`][pdftk].
 
-- [pdftk]
+<!--
+  References
+  -->
 
+<!-- Others -->
 [pdftk]: pdftk.md#combine-multiple-files
diff --git a/knowledge base/compare two pdf files.md b/knowledge base/compare two pdf files.md
index 0bc4130..69693cd 100644
--- a/knowledge base/compare two pdf files.md	
+++ b/knowledge base/compare two pdf files.md	
@@ -1,6 +1,6 @@
 # Compare two PDF files
 
-Install and use `diffpdf` (preferred) or `diff-pdf`:
+Install and use [`diffpdf`][diffpdf] (preferred) or [`diff-pdf`][diff-pdf]:
 
 ```sh
 sudo pacman -S diffpdf
@@ -15,16 +15,34 @@ As an alternative:
 
 ```sh
 # create a pdf with the diff as red pixels
-compare -verbose -debug coder $PDF_1 $PDF_2 -compose src /tmp/$OUT_FILE.tmp
+magick compare -verbose -debug coder $PDF_1 $PDF_2 -compose src /tmp/$OUT_FILE.tmp
 
 # merge the diff-pdf with background PDF_1
 pdftk /tmp/$OUT_FILE.tmp background $PDF_1 output $OUT_FILE
 ```
 
+## Further readings
+
+- [`diffpdf`][diffpdf]
+- [`diff-pdf`][diff-pdf]
+- [ImageMagick]
+- [`pdftk`][pdftk]
+
 ## Sources
 
 - [Compare PDF Files With DiffPDF]
 - [PDF compare on linux command line]
 
+<!--
+  References
+  -->
+
+<!-- Knowledge base -->
+[diffpdf]: diffpdf.md
+[diff-pdf]: diff-pdf.md
+[imagemagick]: imagemagick.md
+[pdftk]: pdftk.md
+
+<!-- Others -->
 [compare pdf files with diffpdf]: https://www.linuxandubuntu.com/home/compare-pdf-files-with-diffpdf-in-ubuntu-linux-debian-fedora-other-derivatives
 [pdf compare on linux command line]: https://stackoverflow.com/questions/6469157/pdf-compare-on-linux-command-line#7228061
diff --git a/knowledge base/create, mount and use an encrypted disk.md b/knowledge base/create, mount and use an encrypted disk.md
index b45c084..e2dcf14 100644
--- a/knowledge base/create, mount and use an encrypted disk.md	
+++ b/knowledge base/create, mount and use an encrypted disk.md	
@@ -52,16 +52,17 @@ All the references in the [further readings] section, plus the following:
 - script: [Create an encrypted BTRFS device]
 - script: [Create an encrypted ZFS device]
 
-<!-- upstream -->
-
-<!-- internal references -->
+<!--
+  References
+  -->
 
+<!-- In-article sections -->
 [further readings]: #further-readings
 
+<!-- Knowledge base -->
 [cryptsetup]: cryptsetup.md
 [encrypted root filesystem]: encrypted%20root%20filesystem.md
 
+<!-- Files -->
 [create an encrypted btrfs device]: scripts/create-an-encrypted-btrfs-device.sh
 [create an encrypted zfs device]: scripts/create-an-encrypted-btrfs-device.sh
-
-<!-- external references -->
diff --git a/knowledge base/enable bluetooth pairing on boot.md b/knowledge base/enable bluetooth pairing on boot.md
index 30af9c9..78b42ac 100644
--- a/knowledge base/enable bluetooth pairing on boot.md	
+++ b/knowledge base/enable bluetooth pairing on boot.md	
@@ -8,6 +8,13 @@ On GNU/Linux:
 1. make sure the `AutoEnable` option in `/etc/bluetooth/main.conf` is set to `true`
 1. [optional] make sure the `FastConnectable` option in `/etc/bluetooth/main.conf` is set to `true`
 
-## Further readings:
+## Further readings
 
+- [Bluetooth]
+
+<!--
+  References
+  -->
+
+<!-- Knowledge base -->
 [bluetooth]: bluetooth.md
diff --git a/knowledge base/encrypted root filesystem.md b/knowledge base/encrypted root filesystem.md
index 62495b6..b6ce156 100644
--- a/knowledge base/encrypted root filesystem.md	
+++ b/knowledge base/encrypted root filesystem.md	
@@ -1,5 +1,10 @@
 # Encrypted root filesystem
 
+## Table of contents <!-- omit in toc -->
+
+1. [Avoiding to type the passphrase twice](#avoiding-to-type-the-passphrase-twice)
+1. [Further readings](#further-readings)
+
 ## Avoiding to type the passphrase twice
 
 Add a key file to your initrd so that you only type the decryption passphrase in the bootloader.
@@ -58,8 +63,12 @@ This works exactly as described above in steps 1-4, except that you don't need t
 - [Avoiding to type the passphrase twice] on the [openSUSE wiki]
 - [Encrypting an entire system] on the [Archlinux wiki]
 
-[Avoiding to type the passphrase twice]: https://en.opensuse.org/SDB:Encrypted_root_file_system#Avoiding_to_type_the_passphrase_twice
-[Encrypting an entire system]: https://wiki.archlinux.org/index.php/Dm-crypt/Encrypting_an_entire_system
+<!--
+  References
+  -->
 
+<!-- Others -->
 [archlinux wiki]: https://wiki.archlinux.org
-[openSUSE wiki]: https://en.opensuse.org/
+[avoiding to type the passphrase twice]: https://en.opensuse.org/SDB:Encrypted_root_file_system#Avoiding_to_type_the_passphrase_twice
+[encrypting an entire system]: https://wiki.archlinux.org/index.php/Dm-crypt/Encrypting_an_entire_system
+[opensuse wiki]: https://en.opensuse.org/
diff --git a/knowledge base/export all variables in a envfile.md b/knowledge base/export all variables in a envfile.md
index 3438093..e7134d2 100644
--- a/knowledge base/export all variables in a envfile.md	
+++ b/knowledge base/export all variables in a envfile.md	
@@ -1,5 +1,10 @@
 # Export all variables in an envfile
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Sources](#sources)
+
 ## TL;DR
 
 ```sh
@@ -12,4 +17,9 @@ set +o allexport
 
 - [Set environment variables from file of key/value pairs]
 
+<!--
+  References
+  -->
+
+<!-- Others -->
 [set environment variables from file of key/value pairs]: https://stackoverflow.com/questions/19331497/set-environment-variables-from-file-of-key-value-pairs#30969768
diff --git a/knowledge base/extract attachments from multipart emails.md b/knowledge base/extract attachments from multipart emails.md
index 1073b4a..9508b54 100644
--- a/knowledge base/extract attachments from multipart emails.md	
+++ b/knowledge base/extract attachments from multipart emails.md	
@@ -16,15 +16,27 @@ In such cases the text file itself contains the multipart message body of the em
 10 j5Dv4g9+fPnTRcX006T++LdYYw7w+i...
 ```
 
-You can use `munpack` to easily extract attachments out of such text files and write them into a proper named files.
+You can use `munpack` to easily extract attachments out of such text files, and save them as properly named files.
 
 ```sh
 $ munpack -f plaintext.eml
 myawesomefile.tar.gz (application/x-gzip)
 ```
 
+## Further readings
+
+- [`munpack`][munpack]
+
 ## Sources
 
 - [Extract attachments from multipart messages]
 
+<!--
+  References
+  -->
+
+<!-- Knowledge base -->
+[munpack]: munpack.md
+
+<!-- Others -->
 [extract attachments from multipart messages]: https://liquidat.wordpress.com/2013/08/07/short-tip-extract-attachments-from-multipart-messages/
diff --git a/knowledge base/ffmpeg.md b/knowledge base/ffmpeg.md
index 1eacb53..24912e7 100644
--- a/knowledge base/ffmpeg.md	
+++ b/knowledge base/ffmpeg.md	
@@ -1,5 +1,12 @@
 # ffmpeg
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Format conversion](#format-conversion)
+   1. [Webm to GIF](#webm-to-gif)
+1. [Sources](#sources)
+
 ## TL;DR
 
 ```sh
@@ -25,5 +32,10 @@ The first command creates a palette out of the webm file. The second command con
 - [Convert a webm file to gif]
 - [How to convert a webm video to a gif on the command line]
 
+<!--
+  References
+  -->
+
+<!-- Others -->
 [convert a webm file to gif]: https://mundanecode.com/posts/convert-webm-to-gif
 [how to convert a webm video to a gif on the command line]: https://askubuntu.com/questions/506670/how-to-do-i-convert-an-webm-video-to-a-animated-gif-on-the-command-line
diff --git a/knowledge base/find how long a process has run.md b/knowledge base/find how long a process has run.md
index ed7d403..885187b 100644
--- a/knowledge base/find how long a process has run.md	
+++ b/knowledge base/find how long a process has run.md	
@@ -2,6 +2,12 @@
 
 UNIX and Linux have commands for almost everything; if there is no command, you can check some important files in the `/etc` directory or in the `/proc` virtual filesystem to find out some useful information.
 
+## Table of contents <!-- omit in toc -->
+
+1. [The easy way](#the-easy-way)
+1. [The hackish way](#the-hackish-way)
+1. [Sources](#sources)
+
 ## The easy way
 
 If the program started today, `ps` also shows when:
@@ -36,6 +42,11 @@ Useful if the process started before today:
 
 ## Sources
 
-- [how to find how long a process has run in unix]
+- [How to find how long a process has run in Unix]
 
+<!--
+  References
+  -->
+
+<!-- Others -->
 [how to find how long a process has run in unix]: https://dzone.com/articles/how-to-find-how-long-a-process-has-run-in-unix
diff --git a/knowledge base/funtoo linux.md b/knowledge base/funtoo linux.md
index 91b3dcc..4d22211 100644
--- a/knowledge base/funtoo linux.md	
+++ b/knowledge base/funtoo linux.md	
@@ -1,5 +1,12 @@
 # Funtoo GNU/Linux
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Further readings](#further-readings)
+
+## TL;DR
+
 ```sh
 # Portage update.
 sudo ego sync
@@ -9,9 +16,18 @@ sudo emerge --sync
 ## Further readings
 
 - [Installation] guide
+- [Gentoo Linux]
 - [Portage]
 - [Profiles]
 
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [installation]: https://www.funtoo.org/Install
-[portage]: portage.md
 [profiles]: https://www.funtoo.org/Funtoo_Profiles
+
+<!-- Knowledge base -->
+[gentoo linux]: gentoo%20linux.md
+[portage]: portage.md
diff --git a/knowledge base/gcloud.md b/knowledge base/gcloud.md
index 4c44724..d59f45f 100644
--- a/knowledge base/gcloud.md	
+++ b/knowledge base/gcloud.md	
@@ -1,4 +1,6 @@
-# Google cloud platform CLI <!-- omit in toc -->
+# Google cloud platform CLI
+
+## Table of contents <!-- omit in toc -->
 
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
@@ -70,14 +72,25 @@ gcloud auth revoke account
 - [Kubectl cluster access]
 - [Gcloud config configurations]
 
-[gcloud cheat-sheet]: https://cloud.google.com/sdk/gcloud/reference/cheat-sheet
-[gcloud config configurations]: https://cloud.google.com/sdk/gcloud/reference/config/configurations
-[kubectl cluster access]: https://cloud.google.com/kubernetes-engine/docs/how-to/cluster-access-for-kubectl
-
 ## Sources
 
+All the references in the [further readings] section, plus the following:
+
 - [How to run gcloud command line using a service account]
 - [How to change the active configuration profile in gcloud]
 
+<!--
+  References
+  -->
+
+<!-- Upstream -->
+[gcloud cheat-sheet]: https://cloud.google.com/sdk/gcloud/reference/cheat-sheet
+[gcloud config configurations]: https://cloud.google.com/sdk/gcloud/reference/config/configurations
+[kubectl cluster access]: https://cloud.google.com/kubernetes-engine/docs/how-to/cluster-access-for-kubectl
+
+<!-- In-article sections -->
+[further readings]: #further-readings
+
+<!-- Others -->
 [how to change the active configuration profile in gcloud]: https://stackoverflow.com/questions/35744901/how-to-change-the-active-configuration-profile-in-gcloud#35750001
 [how to run gcloud command line using a service account]: https://pnatraj.medium.com/how-to-run-gcloud-command-line-using-a-service-account-f39043d515b9
diff --git a/knowledge base/gsutils.md b/knowledge base/gcp/gsutil.md
similarity index 84%
rename from knowledge base/gsutils.md
rename to knowledge base/gcp/gsutil.md
index 5e41890..1354842 100644
--- a/knowledge base/gsutils.md	
+++ b/knowledge base/gcp/gsutil.md	
@@ -1,4 +1,4 @@
-# Gsutils
+# Gsutil
 
 ## TL;DR
 
@@ -14,4 +14,9 @@ gsutil rb gs://${BUCKET_NAME}
 
 - [Deleting buckets]
 
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [deleting buckets]: https://cloud.google.com/storage/docs/deleting-buckets
diff --git a/knowledge base/gentoo linux.md b/knowledge base/gentoo linux.md
index 0394987..49e6c30 100644
--- a/knowledge base/gentoo linux.md	
+++ b/knowledge base/gentoo linux.md	
@@ -3,5 +3,12 @@
 ## Further readings
 
 - [Portage]
+- [Funtoo Linux]
 
+<!--
+  References
+  -->
+
+<!-- Knowledge base -->
+[funtoo linux]: funtoo%20linux.md
 [portage]: portage.md
diff --git a/knowledge base/gitlab.md b/knowledge base/gitlab.md
index 097b8c8..f1ef33c 100644
--- a/knowledge base/gitlab.md	
+++ b/knowledge base/gitlab.md	
@@ -369,7 +369,11 @@ All the references in the [further readings] section, plus the following:
 - [Configuring private dns zones and upstream nameservers in kubernetes]
 - [Using GitLab token to clone without authentication]
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [adding and removing kubernetes clusters]: https://docs.gitlab.com/ee/user/project/clusters/add_remove_clusters.html
 [chart]: https://docs.gitlab.com/charts/
 [command-line options]: https://docs.gitlab.com/charts/installation/command-line-options.html
@@ -381,9 +385,9 @@ All the references in the [further readings] section, plus the following:
 [runners on kubernetes]: https://docs.gitlab.com/runner/install/kubernetes.html
 [tls]: https://docs.gitlab.com/charts/installation/tls.html
 
-<!-- internal references -->
+<!-- In-article sections -->
 [further readings]: #further-readings
 
-<!-- external references -->
+<!-- Others -->
 [configuring private dns zones and upstream nameservers in kubernetes]: https://kubernetes.io/blog/2017/04/configuring-private-dns-zones-upstream-nameservers-kubernetes/
 [using gitlab token to clone without authentication]: https://stackoverflow.com/questions/25409700/using-gitlab-token-to-clone-without-authentication#29570677
diff --git a/knowledge base/golang.md b/knowledge base/golang.md
index 7ab0760..d34ea01 100644
--- a/knowledge base/golang.md	
+++ b/knowledge base/golang.md	
@@ -6,7 +6,6 @@
 1. [JSON data](#json-data)
 1. [Create a container image of a Go app](#create-a-container-image-of-a-go-app)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## Inspect a variable
 
@@ -27,16 +26,11 @@ See [building minimal docker containers for go applications] and [create the sma
 - [Deserializing JSON in Go a tutorial]
 - [How to print struct variables in console]
 
-## Sources
+<!--
+  References
+  -->
 
-All the references in the [further readings] section, plus the following:
-
-<!-- upstream -->
-
-<!-- internal references -->
-[further readings]: #further-readings
-
-<!-- external references -->
+<!-- Others -->
 [building minimal docker containers for go applications]: https://www.cloudbees.com/blog/building-minimal-docker-containers-for-go-applications/
 [create the smallest and secured golang docker image based on scratch]: https://medium.com/@chemidy/create-the-smallest-and-secured-golang-docker-image-based-on-scratch-4752223b7324
 [deserializing json in go a tutorial]: https://medium.com/@fsufitch/deserializing-json-in-go-a-tutorial-d042412958ea
diff --git a/knowledge base/google chrome.md b/knowledge base/google chrome.md
index 7842757..b41dcdb 100644
--- a/knowledge base/google chrome.md	
+++ b/knowledge base/google chrome.md	
@@ -1,5 +1,11 @@
 # Google Chrome
 
+## Table of contents <!-- omit in toc -->
+
+1. [Troubleshooting](#troubleshooting)
+   1. [No "Proceed Anyway" option on NET::ERR\_CERT\_INVALID in Chrome on MacOS](#no-proceed-anyway-option-on-neterr_cert_invalid-in-chrome-on-macos)
+1. [Sources](#sources)
+
 ## Troubleshooting
 
 ### No "Proceed Anyway" option on NET::ERR_CERT_INVALID in Chrome on MacOS
@@ -12,4 +18,9 @@ There's a secret passphrase built into the error page. Just make sure the page i
 
 - [No "Proceed Anyway" option on NET::ERR_CERT_INVALID in Chrome on MacOS]
 
+<!--
+  References
+  -->
+
+<!-- Others -->
 [no "proceed anyway" option on net::err_cert_invalid in chrome on macos]: https://stackoverflow.com/questions/58802767/no-proceed-anyway-option-on-neterr-cert-invalid-in-chrome-on-macos#58957322
diff --git a/knowledge base/google search.md b/knowledge base/google search.md
index 6b480a2..cf0b341 100644
--- a/knowledge base/google search.md	
+++ b/knowledge base/google search.md	
@@ -1,5 +1,10 @@
 # Google Search
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Sources](#sources)
+
 ## TL;DR
 
 - find an **exact phrase** enclosing it in _quotation marks_ (`""`); it will give back only results that include those same words in that same order:
@@ -36,4 +41,9 @@
 
 - [20 Googling Tricks 99% of People Don't Know About]
 
+<!--
+  References
+  -->
+
+<!-- Others -->
 [20 googling tricks 99% of people don't know about]: https://betterhumans.pub/20-googling-tricks-99-of-people-dont-know-about-465ba0477bec
diff --git a/knowledge base/gopass.md b/knowledge base/gopass.md
index 0379323..bef24f9 100644
--- a/knowledge base/gopass.md	
+++ b/knowledge base/gopass.md	
@@ -192,7 +192,11 @@ All the references in the [further readings] section, plus the following:
 
 - [BrowserPass extension installation guide]
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [config]: https://github.com/gopasspw/gopass/blob/master/docs/config.md
 [documentation]: https://github.com/gopasspw/gopass/tree/master/docs
 [faq]: https://github.com/gopasspw/gopass/blob/master/docs/faq.md
@@ -200,9 +204,9 @@ All the references in the [further readings] section, plus the following:
 [secrets]: https://github.com/gopasspw/gopass/blob/master/docs/secrets.md
 [website]: https://www.gopass.pw/
 
-<!-- internal references -->
+<!-- In-article sections -->
 [further readings]: #further-readings
 
-<!-- external references -->
+<!-- Others -->
 [browserpass extension installation guide]: https://github.com/browserpass/browserpass-extension#
 [woile's cheatsheet]: https://woile.github.io/gopass-cheat-sheet/
diff --git a/knowledge base/gpg.md b/knowledge base/gpg.md
index c1f1ddf..df61bbe 100644
--- a/knowledge base/gpg.md	
+++ b/knowledge base/gpg.md	
@@ -1,5 +1,25 @@
 # GnuPG
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Encryption](#encryption)
+1. [Decryption](#decryption)
+1. [Key export](#key-export)
+1. [Key import](#key-import)
+1. [Key trust](#key-trust)
+1. [Unattended key generation](#unattended-key-generation)
+1. [Change a key's password](#change-a-keys-password)
+1. [Put comments in a message or file](#put-comments-in-a-message-or-file)
+1. [Use a GPG key for SSH authentication](#use-a-gpg-key-for-ssh-authentication)
+    1. [Create an authentication subkey](#create-an-authentication-subkey)
+    1. [Enable SSH to use the GPG subkey](#enable-ssh-to-use-the-gpg-subkey)
+    1. [Share the GPG-SSH key](#share-the-gpg-ssh-key)
+1. [Troubleshooting](#troubleshooting)
+    1. [`gpg failed to sign the data; fatal: failed to write commit object`](#gpg-failed-to-sign-the-data-fatal-failed-to-write-commit-object)
+1. [Further readings](#further-readings)
+1. [Sources](#sources)
+
 ## TL;DR
 
 ```sh
@@ -345,6 +365,8 @@ export GPG_TTY=$(tty)
 
 ## Sources
 
+All the references in the [further readings] section, plus the following:
+
 - [Decrypt multiple openpgp files in a directory]
 - [ask redhat]
 - [how can i remove the passphrase from a gpg2 private key?]
@@ -354,11 +376,18 @@ export GPG_TTY=$(tty)
 - [How to renew a (soon to be) expired GPG key]
 - [Renew GPG key]
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [commonly seen problems]: https://www.gnupg.org/documentation/manuals/gnupg/Common-Problems.html
 [unattended key generation]: https://www.gnupg.org/documentation/manuals/gnupg/Unattended-GPG-key-generation.html
 
-<!-- external references -->
+<!-- In-article sections -->
+[further readings]: #further-readings
+
+<!-- Others -->
 [ask redhat]: https://access.redhat.com/solutions/2115511
 [can you manually add a comment to a pgp public key block and not break it?]: https://stackoverflow.com/questions/58696139/can-you-manually-add-a-comment-to-a-pgp-public-key-block-and-not-break-it#58696634
 [decrypt multiple openpgp files in a directory]: https://stackoverflow.com/questions/18769290/decrypt-multiple-openpgp-files-in-a-directory/42431810#42431810
diff --git a/knowledge base/grep the standard error stream.md b/knowledge base/grep the standard error stream.md
index 9810e6e..01e89a7 100644
--- a/knowledge base/grep the standard error stream.md	
+++ b/knowledge base/grep the standard error stream.md	
@@ -38,4 +38,9 @@ command 1>/dev/null 2> >(grep -oP "(.*)(?=pattern)")
 
 [stackexchange]: https://unix.stackexchange.com
 
+<!--
+  References
+  -->
+
+<!-- Others -->
 [how to grep the standard error stream]: https://unix.stackexchange.com/questions/3514/how-to-grep-standard-error-stream-stderr/#3657
diff --git a/knowledge base/grep.md b/knowledge base/grep.md
index 07cda36..b567dc6 100644
--- a/knowledge base/grep.md	
+++ b/knowledge base/grep.md	
@@ -1,5 +1,15 @@
 # Grep
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Variants](#variants)
+   1. [Archive-related variants](#archive-related-variants)
+   1. [PDFgrep](#pdfgrep)
+1. [Gotchas](#gotchas)
+1. [Further readings](#further-readings)
+1. [Sources](#sources)
+
 ## TL;DR
 
 ```sh
@@ -22,7 +32,7 @@ find . -type f -print0 | xargs -0 -n 1 -P "$(nproc)" grep 'pattern'
 grep --color '[[:digit:]]' 'file.txt'
 ```
 
-## Grep variants
+## Variants
 
 - [`egrep`](#egrep) to use regular expressions in search patterns, same as `grep -E`
 - [`fgrep`](#fgrep) to use patterns as fixed strings, same as `grep -F`
@@ -61,19 +71,29 @@ find /path -name '*.pdf' -exec sh -c 'pdftotext "{}" - | grep --with-filename --
 ## Further readings
 
 - [Grep the standard error stream]
-- Knowledge base on [pdfgrep]
-
-[grep the standard error stream]: grep\ the\ standard\ error\ stream.md
-[pdfgrep]: pdfgrep.md
+- [`pdfgrep`][pdfgrep]
 
 ## Sources
 
+All the references in the [further readings] section, plus the following:
+
 - Answer on [StackOverflow] about [how to search contents of multiple pdf files]
 - [Regular expressions in grep with examples]
 - [Parallel grep]
 
-[stackoverflow]: https://stackoverflow.com
+<!--
+  References
+  -->
 
+<!-- In-article sections -->
+[further readings]: #further-readings
+
+<!-- Knowledge base -->
+[grep the standard error stream]: grep%20the%20standard%20error%20stream.md
+[pdfgrep]: pdfgrep.md
+
+<!-- Others -->
 [how to search contents of multiple pdf files]: https://stackoverflow.com/a/4643518
 [parallel grep]: https://www.highonscience.com/blog/2021/03/21/parallel-grep/
 [regular expressions in grep with examples]: https://www.cyberciti.biz/faq/grep-regular-expressions/
+[stackoverflow]: https://stackoverflow.com
diff --git a/knowledge base/keychron.md b/knowledge base/keychron.md
index 60d92ec..a2954b9 100644
--- a/knowledge base/keychron.md	
+++ b/knowledge base/keychron.md	
@@ -1,5 +1,13 @@
 # Keychron
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Further readings](#further-readings)
+1. [Sources](#sources)
+
+## TL;DR
+
 1. set the keyboard to _Windows mode_ using the side switch
 
 1. hold `Fn + X + L` for 4 seconds to set the function key row to _fn mode_
@@ -33,7 +41,11 @@
 - [Keychron fn keys in Linux]
 - [Apple Keyboard] on the [Archlinux wiki]
 
-[archlinux wiki]: https://wiki.archlinux.org
+<!--
+  References
+  -->
 
+<!-- Others -->
 [apple keyboard]: https://wiki.archlinux.org/index.php/Apple_Keyboard
+[archlinux wiki]: https://wiki.archlinux.org
 [keychron fn keys in linux]: https://mikeshade.com/posts/keychron-linux-function-keys
diff --git a/knowledge base/kubernetes/check a pod can connect to an external db.md b/knowledge base/kubernetes/check a pod can connect to an external db.md
index a617fee..20fa22e 100644
--- a/knowledge base/kubernetes/check a pod can connect to an external db.md	
+++ b/knowledge base/kubernetes/check a pod can connect to an external db.md	
@@ -4,7 +4,6 @@
 
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## TL;DR
 
@@ -27,16 +26,10 @@ mysql --host 10.0.2.15 --port 3306 --user root
 - [Kubernetes]
 - [`kubectl`][kubectl]
 
-## Sources
+<!--
+  References
+  -->
 
-All the references in the [further readings] section, plus the following:
-
-<!-- upstream -->
-<!-- in-article references -->
-[further readings]: #further-readings
-
-<!-- internal references -->
+<!-- Knowledge base -->
 [kubectl]: kubectl.md
 [kubernetes]: README.md
-
-<!-- external references -->
diff --git a/knowledge base/kubernetes/drain a node.md b/knowledge base/kubernetes/drain a node.md
index 1c973bf..2caf36d 100644
--- a/knowledge base/kubernetes/drain a node.md	
+++ b/knowledge base/kubernetes/drain a node.md	
@@ -45,13 +45,16 @@ All the references in the [further readings] section, plus the following:
 
 - [How to drain a node in Kubernetes]
 
-<!-- upstream -->
-<!-- in-article references -->
+<!--
+  References
+  -->
+
+<!-- In-article sections -->
 [further readings]: #further-readings
 
-<!-- internal references -->
+<!-- Knowledge base -->
 [kubectl]: kubectl.md
 [kubernetes]: README.md
 
-<!-- external references -->
+<!-- Others -->
 [how to drain a node in kubernetes]: https://linuxhandbook.com/kubectl-drain-node/
diff --git a/knowledge base/kubernetes/get the environment of a process running in a container.md b/knowledge base/kubernetes/get the environment of a process running in a container.md
index 8258270..ef0646e 100644
--- a/knowledge base/kubernetes/get the environment of a process running in a container.md	
+++ b/knowledge base/kubernetes/get the environment of a process running in a container.md	
@@ -28,13 +28,16 @@ All the references in the [further readings] section, plus the following:
 
 - [Get the environment variables of running process in container]
 
-<!-- upstream -->
-<!-- in-article references -->
+<!--
+  References
+  -->
+
+<!-- In-article sections -->
 [further readings]: #further-readings
 
-<!-- internal references -->
+<!-- Knowledge base -->
 [kubectl]: kubectl.md
 [kubernetes]: README.md
 
-<!-- external references -->
+<!-- Others -->
 [get the environment variables of running process in container]: https://unix.stackexchange.com/a/412730
diff --git a/knowledge base/less.md b/knowledge base/less.md
index 4829a9e..78a2db5 100644
--- a/knowledge base/less.md	
+++ b/knowledge base/less.md	
@@ -15,4 +15,11 @@
 
 ## Sources
 
-[case insensitive search]: https://unix.stackexchange.com/questions/116395/less-searches-are-always-case-insensitive#577376
+- [Less searches are always case-insensitive]
+
+<!--
+  References
+  -->
+
+<!-- Others -->
+[less searches are always case-insensitive]: https://unix.stackexchange.com/questions/116395/less-searches-are-always-case-insensitive#577376
diff --git a/knowledge base/limit the cpu usage of a process.md b/knowledge base/limit the cpu usage of a process.md
index 2de8280..3ec6afc 100644
--- a/knowledge base/limit the cpu usage of a process.md	
+++ b/knowledge base/limit the cpu usage of a process.md	
@@ -1,6 +1,6 @@
 # Limit the CPU usage of a process
 
-## TL;DR
+See [`cpulimit`][cpulimit]:
 
 ```sh
 sudo cpulimit -p 'process-id' -l 'cpu-percentage'
@@ -10,4 +10,12 @@ sudo cpulimit -p 'process-id' -l 'cpu-percentage'
 
 - [25 awesome linux command one-Liners]
 
+<!--
+  References
+  -->
+
+<!-- Knowledge base -->
+[cpulimit]: cpulimit.md
+
+<!-- Others -->
 [25 awesome linux command one-liners]: https://betterprogramming.pub/25-awesome-linux-command-one-liners-9495f26f07fb
diff --git a/knowledge base/manjaro linux.md b/knowledge base/manjaro linux.md
index 5245d90..65bc32e 100644
--- a/knowledge base/manjaro linux.md	
+++ b/knowledge base/manjaro linux.md	
@@ -1,5 +1,12 @@
 # Manjaro GNU/Linux
 
+## Table of contents <!-- omit in toc -->
+
+1. [Repositories](#repositories)
+1. [Printing](#printing)
+1. [Further readings](#further-readings)
+1. [Sources](#sources)
+
 ## Repositories
 
 To ensure continued stability and reliability, Manjaro uses its own dedicated software branches rather than relying on those provided by Arch:
@@ -28,14 +35,26 @@ pamac install system-config-printer
 - [Switching branches]
 - [Printing]
 
-[arch linux]: arch%20linux.md
+## Sources
 
+All the references in the [further readings] section, plus the following:
+
+- [Kde Plasma 5.23 not updating]
+
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [branch comparison]: https://manjaro.org/branch-compare
 [printing]: https://wiki.manjaro.org/index.php/Printing
 [switching branches]: https://wiki.manjaro.org/index.php/Switching_Branches
 
-## Sources
+<!-- In-article sections -->
+[further readings]: #further-readings
 
-- [Kde Plasma 5.23 not updating]
+<!-- Knowledge base -->
+[arch linux]: arch%20linux.md
 
+<!-- Others -->
 [kde plasma 5.23 not updating]: https://forum.manjaro.org/t/kde-plasma-5-23-not-updating/88297/4
diff --git a/knowledge base/markdown.md b/knowledge base/markdown.md
index d02a03a..ea47016 100644
--- a/knowledge base/markdown.md	
+++ b/knowledge base/markdown.md	
@@ -302,16 +302,23 @@ All the references in the [further readings] section, plus the following:
 - [slaise/High-level-Markdown]
 - [Syntax highlighting in Markdown]
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [basic syntax]: https://www.markdownguide.org/basic-syntax
 [code blocks]: https://docs.readme.com/rdmd/docs/code-blocks
 [documentation]: https://docs.readme.com/rdmd/docs
 [extended syntax]: https://www.markdownguide.org/extended-syntax/
 
-<!-- internal references -->
+<!-- In-article sections -->
+[further readings]: #further-readings
+
+<!-- Knowledge base -->
 [mermaid.js]: mermaid.js.md
 
-<!-- external references -->
+<!-- Others -->
 [bierner.markdown-mermaid]: https://marketplace.visualstudio.com/items?itemName=bierner.markdown-mermaid
 [escaping backtick in markdown]: https://www.growingwiththeweb.com/2015/06/escaping-backtick-in-markdown.html
 [escaping backticks]: https://www.markdownguide.org/basic-syntax/#escaping-backticks
diff --git a/knowledge base/mdl.md b/knowledge base/mdl.md
index 004c97b..f3653c4 100644
--- a/knowledge base/mdl.md	
+++ b/knowledge base/mdl.md	
@@ -2,6 +2,11 @@
 
 Tool to check markdown files and flag style issues.
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Further readings](#further-readings)
+
 ## TL;DR
 
 ```sh
@@ -20,4 +25,9 @@ mdl -r "~MD013" README.md
 
 - [GitHub]
 
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [github]: https://github.com/markdownlint/markdownlint
diff --git a/knowledge base/mermaid-cli.md b/knowledge base/mermaid-cli.md
index 320a512..ff47289 100644
--- a/knowledge base/mermaid-cli.md	
+++ b/knowledge base/mermaid-cli.md	
@@ -6,7 +6,6 @@ CLI for mermaid. Takes a mermaid definition file as input and generates an `svg`
 
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## TL;DR
 
@@ -22,15 +21,12 @@ mmdc -i 'input.mmd' -o 'output.svg'
 
 - [mermaid.js]
 
-## Sources
+<!--
+  References
+  -->
 
-All the references in the [further readings] section, plus the following:
-
-<!-- upstream -->
+<!-- Upstream -->
 [github]: https://github.com/mermaid-js/mermaid-cli
 
-<!-- internal references -->
-[further readings]: #further-readings
+<!-- Knowledge base -->
 [mermaid.js]: mermaid.js.md
-
-<!-- external references -->
diff --git a/knowledge base/mermaid.js.md b/knowledge base/mermaid.js.md
index c0316fc..5555bbd 100644
--- a/knowledge base/mermaid.js.md	
+++ b/knowledge base/mermaid.js.md	
@@ -18,12 +18,14 @@ Mermaid.js offers a [live editor] to check the graph code.
 - [Markdown]
 - [mermaid-cli]
 
-<!-- upstream -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [documentation]: https://mermaid.js.org/intro/
 [live editor]: https://mermaid.live
 
-<!-- internal references -->
+<!-- Knowledge base -->
 [markdown]: markdown.md
 [mermaid-cli]: mermaid-cli.md
-
-<!-- external references -->
diff --git a/knowledge base/microos.md b/knowledge base/microos.md
index fd56e10..5667bd5 100644
--- a/knowledge base/microos.md	
+++ b/knowledge base/microos.md	
@@ -1,5 +1,12 @@
 # OpenSUSE MicroOS
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Setting up MicroOS as a desktop OS](#setting-up-microos-as-a-desktop-os)
+1. [Further readings](#further-readings)
+1. [Sources](#sources)
+
 ## TL;DR
 
 Every set of changes to the underlying system is executed on a new inactive snapshot, which will be the one the system will boot into on the next reboot.
@@ -28,13 +35,19 @@ See [MicroOS Desktop] for more and updated information.
 - [Flatpak]
 - [Toolbox]
 
-[flatpak]: flatpak.md
-[toolbox]: toolbox.md
-
 ## Sources
 
 - [MicroOS Desktop]
 - [MicroOS Portal]
 
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [microos desktop]: https://opensuse.github.io/openSUSE-docs-revamped-temp/microos_getting_started/
 [microos portal]: https://en.opensuse.org/Portal:MicroOS
+
+<!-- Knowledge base -->
+[flatpak]: flatpak.md
+[toolbox]: toolbox.md
diff --git a/knowledge base/mitmproxy.md b/knowledge base/mitmproxy.md
index f6dbd5c..eaf14d6 100644
--- a/knowledge base/mitmproxy.md	
+++ b/knowledge base/mitmproxy.md	
@@ -6,7 +6,6 @@ Free and open source set of tools which provide an interactive, SSL/TLS-capable
 
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
 
 ## TL;DR
 
@@ -20,16 +19,10 @@ brew install 'mitmproxy'
 - [Website]
 - [Documentation]
 
-## Sources
+<!--
+  References
+  -->
 
-All the references in the [further readings] section, plus the following:
-
-<!-- upstream -->
+<!-- Upstream -->
 [documentation]: https://docs.mitmproxy.org/stable/
 [website]: https://mitmproxy.org/
-
-<!-- in-article references -->
-[further readings]: #further-readings
-
-<!-- internal references -->
-<!-- external references -->
diff --git a/knowledge base/mkpasswd.md b/knowledge base/mkpasswd.md
index 6095791..8aa7cab 100644
--- a/knowledge base/mkpasswd.md	
+++ b/knowledge base/mkpasswd.md	
@@ -1,6 +1,6 @@
 # Debian's mkpasswd
 
-Crypts a given password using crypt(3).
+Crypts a given password using `crypt(3)`.
 
 ```sh
 mkpasswd [OPTIONS]... [PASSWORD [SALT]]
diff --git a/knowledge base/mktemp.md b/knowledge base/mktemp.md
index 5c3b42c..07849a7 100644
--- a/knowledge base/mktemp.md	
+++ b/knowledge base/mktemp.md	
@@ -2,6 +2,11 @@
 
 Creates a unique temporary file or directory and returns the absolute path to it.
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Further readings](#further-readings)
+
 ## TL;DR
 
 ```sh
@@ -28,4 +33,9 @@ mktemp -t "txt"
 
 - [Man page]
 
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [man page]: https://www.gnu.org/software/autogen/mktemp.html
diff --git a/knowledge base/mount samba shares from a unix client.md b/knowledge base/mount samba shares from a unix client.md
index 8776be2..dbd67c3 100644
--- a/knowledge base/mount samba shares from a unix client.md	
+++ b/knowledge base/mount samba shares from a unix client.md	
@@ -1,5 +1,10 @@
 # Mount samba shares from a unix client
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Further readings](#further-readings)
+
 ## TL;DR
 
 ```sh
@@ -10,4 +15,9 @@ sudo mount -t cifs -o user=my-user //nas.local/shared_folder local_folder
 
 - [Mounting samba shares from a unix client]
 
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [mounting samba shares from a unix client]: https://wiki.samba.org/index.php/Mounting_samba_shares_from_a_unix_client
diff --git a/knowledge base/visual studio code.md b/knowledge base/visual studio code.md
index 9d4fe77..60e2d4d 100644
--- a/knowledge base/visual studio code.md	
+++ b/knowledge base/visual studio code.md	
@@ -1,5 +1,7 @@
 # Visual Studio Code
 
+## Table of contents <!-- omit in toc -->
+
 1. [Handy keyboard shortcuts](#handy-keyboard-shortcuts)
 1. [Handy settings](#handy-settings)
    1. [Built-in](#built-in)
@@ -107,12 +109,15 @@ and if not, change them.
 
 ## Sources
 
-- [using extensions in compiled vscode]
+- [Using extensions in compiled VSCode]
 
-<!-- product's references -->
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [network connections in visual studio code]: https://code.visualstudio.com/docs/setup/network
 [official product.json]: https://github.com/Microsoft/vscode/blob/master/product.json
 
-<!-- internal references -->
-<!-- external references -->
+<!-- Others -->
 [using extensions in compiled vscode]: https://stackoverflow.com/questions/44057402/using-extensions-in-compiled-vscode#45291490
diff --git a/knowledge base/vivaldi.md b/knowledge base/vivaldi.md
index 731bd73..1fedde7 100644
--- a/knowledge base/vivaldi.md	
+++ b/knowledge base/vivaldi.md	
@@ -1,5 +1,7 @@
 # Vivaldi browser
 
+## Network activity
+
 | URL                 | Ports      | Description                 |
 | ------------------- | ---------- | --------------------------- |
 | bifrost.vivaldi.com | 443, 15674 | Sync settings               |
@@ -9,4 +11,9 @@
 
 - [Decoding network activity in Vivaldi]
 
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [decoding network activity in vivaldi]: https://vivaldi.com/blog/decoding-network-activity-in-vivaldi/
diff --git a/knowledge base/wake a host from lan.md b/knowledge base/wake a host from lan.md
index 9f43f8c..3f47361 100644
--- a/knowledge base/wake a host from lan.md	
+++ b/knowledge base/wake a host from lan.md	
@@ -5,16 +5,11 @@ The host needs to support wake-on-LAN and have it enabled.
 ## Table of contents <!-- omit in toc -->
 
 1. [TL;DR](#tldr)
-1. [Further readings](#further-readings)
 1. [Sources](#sources)
 
 ## TL;DR
 
-Use [`wakeonlan`][wakeonlan].
-
-## Further readings
-
-- [`wakeonlan`][wakeonlan]
+See [`wakeonlan`][wakeonlan].
 
 ## Sources
 
@@ -22,13 +17,15 @@ All the references in the [further readings] section, plus the following:
 
 - [How to wake up computers using Linux by sending magic packets]
 
-<!-- upstream -->
-<!-- internal references -->
+<!--
+  References
+  -->
 
+<!-- In-article sections -->
 [further readings]: #further-readings
 
+<!-- Knowledge base -->
 [wakeonlan]: wakeonlan.md
 
-<!-- external references -->
-
+<!-- Others -->
 [how to wake up computers using linux by sending magic packets]: https://www.cyberciti.biz/tips/linux-send-wake-on-lan-wol-magic-packets.html
diff --git a/knowledge base/wakeonlan.md b/knowledge base/wakeonlan.md
index 70ade7d..13367a2 100644
--- a/knowledge base/wakeonlan.md	
+++ b/knowledge base/wakeonlan.md	
@@ -33,15 +33,17 @@ wakeonlan -n '11:22:33:44:55:66' -i '192.168.100.3'
 
 All the references in the [further readings] section, plus the following:
 
-- [wake a host from lan]
+- [Wake a host from LAN]
 
-<!-- upstream -->
-<!-- internal references -->
+<!--
+  References
+  -->
 
+<!-- In-article sections -->
 [further readings]: #further-readings
 
+<!-- Knowledge base -->
 [wake a host from lan]: wake%20a%20host%20from%20lan.md
 
-<!-- external references -->
-
+<!-- Others -->
 [man page]: https://www.unix.com/man-page/debian/1/WAKEONLAN/
diff --git a/knowledge base/windows.md b/knowledge base/windows.md
index 66a0886..4e2d026 100644
--- a/knowledge base/windows.md	
+++ b/knowledge base/windows.md	
@@ -1,4 +1,11 @@
-# Microsoft windows
+# Microsoft Windows
+
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Disable fast startup on Windows 10](#disable-fast-startup-on-windows-10)
+1. [Further readings](#further-readings)
+1. [Sources](#sources)
 
 ## TL;DR
 
@@ -31,4 +38,9 @@ Test-NetConnection -Port 443 -ComputerName 192.168.0.1 -InformationLevel Detaile
 
 - [How to disable Windows 10 fast startup (and why you'd want to)]
 
+<!--
+  References
+  -->
+
+<!-- Others -->
 [how to disable windows 10 fast startup (and why you'd want to)]: https://www.windowscentral.com/how-disable-windows-10-fast-startup
diff --git a/knowledge base/winget.md b/knowledge base/winget.md
index a15a03b..40e7b34 100644
--- a/knowledge base/winget.md	
+++ b/knowledge base/winget.md	
@@ -1,5 +1,13 @@
 # WinGet
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Installation](#installation)
+   1. [Through the Microsoft Store (recommended)](#through-the-microsoft-store-recommended)
+   1. [Manual installation](#manual-installation)
+1. [Further readings](#further-readings)
+
 ## TL;DR
 
 ```powershell
@@ -39,10 +47,16 @@ Once you have received the updated App Installer you should be able to execute `
 
 - Tool [overview]
 
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [overview]: https://docs.microsoft.com/en-us/windows/package-manager/winget/
 [releases page]: https://github.com/microsoft/winget-cli/releases
 [repository]: https://github.com/microsoft/winget-cli
 
+<!-- Others -->
 [app installer package]: https://www.microsoft.com/p/app-installer/9nblggh4nns1
 [join the preview flight ring]: http://aka.ms/winget-InsiderProgram
 [windows insider]: https://insider.windows.com/
diff --git a/knowledge base/xclip.md b/knowledge base/xclip.md
index 42f4ccd..59a41d8 100644
--- a/knowledge base/xclip.md	
+++ b/knowledge base/xclip.md	
@@ -10,4 +10,9 @@ xclip -selection clipboard < file
 
 - [copy the contents of a file into the clipboard without displaying its contents]
 
+<!--
+  References
+  -->
+
+<!-- Others -->
 [copy the contents of a file into the clipboard without displaying its contents]: https://unix.stackexchange.com/questions/211817/copy-the-contents-of-a-file-into-the-clipboard-without-displaying-its-contents#211826
diff --git a/knowledge base/xdg base directory.md b/knowledge base/xdg base directory.md
index dca54a2..ff7adf1 100644
--- a/knowledge base/xdg base directory.md	
+++ b/knowledge base/xdg base directory.md	
@@ -27,16 +27,19 @@ All paths set in these environment variables must be absolute. By specification,
 
 ## Sources
 
-- [Arch Linux Wiki page]
-
 All the references in the [further readings] section, plus the following:
 
-<!-- upstream -->
+- [Arch Linux Wiki page]
+
+<!--
+  References
+  -->
+
+<!-- Upstream -->
 [specifications]: https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
 
-<!-- in-article references -->
+<!-- In-article sections -->
 [further readings]: #further-readings
 
-<!-- internal references -->
-<!-- external references -->
+<!-- Others -->
 [arch linux wiki page]: https://wiki.archlinux.org/title/XDG_Base_Directory
diff --git a/knowledge base/yadm.md b/knowledge base/yadm.md
index 288e436..b741a77 100644
--- a/knowledge base/yadm.md	
+++ b/knowledge base/yadm.md	
@@ -2,6 +2,14 @@
 
 Yet Another Dotfile Manager.
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Class and overrides](#class-and-overrides)
+1. [Alternate files](#alternate-files)
+1. [Templates](#templates)
+1. [Further readings](#further-readings)
+
 ## TL;DR
 
 ```sh
@@ -86,11 +94,15 @@ Check the official docs on [templates] for the updated information.
 
 ## Further readings
 
-- the project's [homepage]
+- [Website]
 - [Alternate files]
 - [Templates]
 
-[homepage]: https://yadm.io/
+<!--
+  References
+  -->
 
+<!-- Upstream -->
 [alternate files]: https://yadm.io/docs/alternates
 [templates]: https://yadm.io/docs/templates
+[website]: https://yadm.io/