diff --git a/.vscode/settings.json b/.vscode/settings.json
index 0f5a680..0ad21a7 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -16,6 +16,7 @@
         "cfengine",
         "chattr",
         "chezmoi",
+        "chpass",
         "chsh",
         "clamav",
         "clamd",
@@ -76,6 +77,7 @@
         "pinentry",
         "pkexec",
         "polkit",
+        "portsnap",
         "pvresize",
         "radeon",
         "replicatedctl",
@@ -91,6 +93,7 @@
         "subvolume",
         "swapfile",
         "swapon",
+        "sysrc",
         "tclsh",
         "templating",
         "tfvars",
diff --git a/examples/freebsd.initial-config.sh b/examples/freebsd.initial-config.sh
new file mode 100644
index 0000000..9a37657
--- /dev/null
+++ b/examples/freebsd.initial-config.sh
@@ -0,0 +1,36 @@
+#!/usr/bin/env sh
+
+if [ "$(id -ru)" -eq 0 ]
+then
+	echo "Run this again as 'root'"
+	exit 1
+fi
+
+# Package management
+
+pkg bootstrap
+pkg update
+pkg install -y \
+	'vim' \
+	'zsh' 'zsh-autosuggestions' 'zsh-completions' 'zsh-navigation-tools' 'zsh-syntax-highlighting'
+
+# Non-'root' user management
+
+pw groupmod 'wheel' -m 'username'
+cat > '/home/username/.zshrc' <<-EOF
+	source /usr/local/share/zsh-syntax-highlighting/zsh-syntax-highlighting.zsh
+	source /usr/local/share/zsh-autosuggestions/zsh-autosuggestions.zsh
+	source /usr/local/share/zsh-navigation-tools/zsh-navigation-tools.plugin.zsh
+
+	HISTFILE=~/.histfile
+	HISTSIZE=100000
+	SAVEHIST=100000
+	bindkey -e
+
+	zstyle :compinstall filename ~/.zshrc
+	autoload -Uz compinit
+	compinit
+EOF
+chown 'username':'usergroup' '/home/username/.zshrc'
+chmod 'u=rw,go=r' '/home/username/.zshrc'
+chpass -s "$(grep 'bin/zsh' '/etc/shells')" 'username'
diff --git a/examples/freebsd.virtualbox.guest-additions.sh b/examples/freebsd.virtualbox.guest-additions.sh
new file mode 100644
index 0000000..5d855fb
--- /dev/null
+++ b/examples/freebsd.virtualbox.guest-additions.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env sh
+
+if [ "$(id -ru)" -eq 0 ]
+then
+	echo "Run this again as 'root'"
+	exit 1
+fi
+
+# Package management
+# Use 'virtualbox-ose-additions-nox11' for console-only systems.
+
+pkg bootstrap
+pkg update
+pkg install -y 'virtualbox-ose-additions'
+
+# Start VirtualBox services at boot
+
+sysrc vboxguest_enable="YES"
+sysrc vboxservice_enable="YES"
+
+# NTP workaround
+# Needed if NTP or NTPDate are used
+
+sysrc vboxservice_flags="--disable-timesync"
diff --git a/knowledge base/freebsd.md b/knowledge base/freebsd.md
index 1d62fa4..73f05ce 100644
--- a/knowledge base/freebsd.md	
+++ b/knowledge base/freebsd.md	
@@ -1,34 +1,204 @@
 # FreeBSD
 
+## Table of contents <!-- omit in toc -->
+
+1. [TL;DR](#tldr)
+1. [Utilities worth noting](#utilities-worth-noting)
+1. [The `rc.conf` files](#the-rcconf-files)
+1. [Package management](#package-management)
+   1. [Manage binary packages with `pkg`](#manage-binary-packages-with-pkg)
+   1. [Manage ports from the Ports collection](#manage-ports-from-the-ports-collection)
+1. [Enable time sync for the NTP server](#enable-time-sync-for-the-ntp-server)
+1. [VirtualBox Guest Additions](#virtualbox-guest-additions)
+1. [Further readings](#further-readings)
+1. [Sources](#sources)
+
 ## TL;DR
 
 ```sh
-# Initialize package managers.
-portsnap auto
+# Read manual pages.
+man 5 'rc.conf'
+
+# Search for keywords in the manual page descriptions.
+man -k 'mail'
+
+# Edit files.
+edit 'path/to/file'
+
+# Become 'root' from user sessions.
+# The user must know root's password *and* be member of the 'wheel' group.
+# Use '-' at the end to also load root's environment.
+su
+su -
+
+# Add new members to groups.
+pw groupmod 'group_name' -m 'username'
+pw groupmod 'group_name' -m 'username_1','username_N'
+
+# Replace all members in groups.
+pw groupmod 'group_name' -M 'username'
+pw groupmod 'group_name' -M 'username_1','username_N'
+
+# Change users' default shell.
+chpass -s 'path/to/shell' 'username'
+chpass -s "$(grep 'bin/zsh' '/etc/shells')" 'username'
+
+# Start services at boot.
+sysrc ntpd_enable="YES"
+sysrc vboxguest_enable="YES"
+
+# Get the current system's version.
+freebsd-version
+
+# Upgrade the system.
+# Maintains the current version.
+freebsd-update fetch && \
+freebsd-update install
+
+# Upgrade the system to a newer version.
+freebsd-update upgrade -r '13.2-RELEASE' && \
+freebsd-update install
+
+# Initialize the package managers.
 pkg bootstrap
+portsnap auto
+
+# Update the package cache.
+pkg update
+
+# Search for packages.
+pkg search 'bash'
+
+# Install packages.
+pkg install 'vim'
+pkg install -y 'zsh' 'zsh-autosuggestions'
+
+# Upgrade packages.
+pkg upgrade
+pkg install -y 'zsh' 'zsh-autosuggestions'
+
+# Check for known vulnerabilities in *installed* applications.
+pkg audit -F
+pkg audit -Fr 'sqlite'
 ```
 
-## Utilities worth noticing
+## Utilities worth noting
 
 - `bsdinstall`
 - `bsdconfig`
 
-## NTP time sync
+## The `rc.conf` files
 
-```conf
-# file /etc/rc.conf
-ntpd_enable="YES"
-ntpd_sync_on_start="YES"
+The `rc.conf` files contain information about the local host name, configuration details for any network interfaces and which services should be started up at system boot.<br/>
+Options are set with `name=value` assignments using the `sh(1)` syntax, and the files are included by the various generic startup scripts in `/etc` which than make decision about their internal actions according to their contents.
+
+The `sysrc(8)` command provides a scripting interface to programmatically modify system configuration files.
+
+The `/etc/defaults/rc.conf` file specifies the **default** settings for all the available options. At its very end, it sources, in order:
+
+- the `/etc/rc.conf` file, to allow system administrators to override such default values for the local system, and
+- the `/etc/defaults/vendor.conf` file, to allow vendors to override system defaults.
+
+In the very same way, the `/etc/rc.conf.local` file is used to override settings in `/etc/rc.conf` for historical reasons.
+
+In addition to `/etc/rc.conf.local`, one can also place smaller configuration files for each `rc(8)` script in the `/etc/rc.conf.d` or `⟨dir⟩/rc.conf.d` directories specified in `local_startup`, all of which will then be included by the `load_rc_config` function.
+
+For jail configurations, one could use the `/etc/rc.conf.d/jail` file to store configuration options specific to jails only.<br/>
+If `local_startup` contains `/usr/local/etc/rc.d` and `/opt/conf`, `/usr/local/rc.conf.d/jail` and `/opt/conf/rc.conf.d/jail` will be loaded too. If `⟨dir⟩/rc.conf.d/⟨name⟩` is a directory, all the files in it will be loaded too.
+
+See the contents of `man 5 rc.conf` for more information.
+
+## Package management
+
+Requires:
+
+- [`pkg`][manage binary packages with pkg] if one wants to deal with binary packages;
+- the [Ports collection][manage ports from the ports collection] if one wants to compile and install source code in an automated way.
+
+See [Installing applications] for more information.
+
+### Manage binary packages with `pkg`
+
+```sh
+# Bootstrap `pkg`.
+# Need to be run as 'root'.
+pkg bootstrap
+
+# Update the package cache.
+pkg update
+
+# Get help on the command.
+pkg help
+pkg help 'search'
+
+# Search for packages.
+pkg search 'bash'
+
+# Install packages.
+pkg install 'vim'
+pkg install -y 'zsh' 'zsh-autosuggestions'
 ```
 
+### Manage ports from the Ports collection
+
+TODO
+
+## Enable time sync for the NTP server
+
+```sh
+sysrc ntpd_enable="YES"
+sysrc ntpd_sync_on_start="YES"
+```
+
+## VirtualBox Guest Additions
+
+1. Install the additions.<br/>
+   Use the `-nox11` package for console-only guests.
+
+   ```sh
+   pkg update
+   pkg install -y 'virtualbox-ose-additions'
+   ```
+
+1. Enable the services at boot:
+
+   ```sh
+   sysrc vboxguest_enable="YES"
+   sysrc vboxservice_enable="YES"
+   ```
+
+1. If `ntp` or `ntpdate` are used, disable the additions' time sync:
+
+   ```sh
+   sysrc vboxservice_flags="--disable-timesync"
+   ```
+
+## Further readings
+
+- The [FreeBSD Handbook]
+- [`rc.conf`'s man page][rc.conf man page]
+- [Installing applications]
+- [Using the Ports collection]
+
 ## Sources
 
-- [Ports]
+All the references in the [further readings] section, plus the following:
+
 - [NTPdate - not updating to current time]
 - [Boinc]
 - [sbz's FreeBSD commands cheat-sheet]
 
+<!-- project's references -->
+[freebsd handbook]: https://docs.freebsd.org/en/books/handbook/
+[Installing applications]: https://docs.freebsd.org/en/books/handbook/ports/
+[rc.conf man page]: https://man.freebsd.org/cgi/man.cgi?rc.conf(5)
+[using the ports collection]: https://docs.freebsd.org/en/books/handbook/ports/#ports-using
+
+<!-- internal references -->
+[manage binary packages with pkg]: #manage-binary-packages-with-pkg
+[manage ports from the ports collection]: #manage-ports-from-the-ports-collection
+
+<!-- external references -->
 [boinc]: https://people.freebsd.org/~pav/boinc.html
 [ntpdate - not updating to current time]: https://forums.freebsd.org/threads/ntpdate-not-updating-to-current-time.72847/
-[ports]: https://docs.freebsd.org/en/books/handbook/ports/
 [sbz's freebsd commands cheat-sheet]: https://github.com/sbz/freebsd-commands