diff --git a/knowledge base/exiftool.md b/knowledge base/exiftool.md
index 3d73cb1..432ca4f 100644
--- a/knowledge base/exiftool.md	
+++ b/knowledge base/exiftool.md	
@@ -1,42 +1,85 @@
 # ExifTool
 
-Platform-independent Perl library and command-line application for reading, writing and editing meta information in a wide variety of files.<br/>
+Platform-independent Perl library and command-line application for reading, writing and editing meta information in a
+wide variety of files.<br/>
 It supports many different metadata formats as well as the maker notes of many digital cameras.
 
-## Table of contents <!-- omit in toc -->
-
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
+   1. [Sources](#sources)
 
 ## TL;DR
 
+<details>
+  <summary>Setup</summary>
+
 ```sh
 # Installation.
 brew install 'exiftool'
+sudo zypper in 'exiftool'
 ```
 
+</details>
+
+<details>
+  <summary>Usage</summary>
+
+```sh
+# Show metadata in files.
+exiftool 'path/to/image-1.jpg' 'path/to/image-n.jpg'
+
+# Only show specific metadata tags.
+# Tags selection is case *in*sensitive.
+# Spaces in tags must be removed from the selector.
+exiftool -'tagName' 'path/to/image-1.jpg'
+
+# Add or edit metadata tags.
+exiftool -author='linuxConfig' -title='Linux penguin' 'image.jpg'
+
+# Remove metadata tags.
+exiftool -author='' -title= 'image.jpg'
+exiftool -all='' 'image.jpg'
+```
+
+</details>
+
+<details>
+  <summary>Real world use cases</summary>
+
+```sh
+# It would be the same to use '-imageheight', '-ImageHeight' or '-imageHeight'.
+exiftool -ImageHeight 'Downloads/meme.png'
+
+# Print formatted date/time for all JPG files in the current directory.
+exiftool -d "%r %a, %B %e, %Y" -DateTimeOriginal -S -s *'.jpg'
+
+# Extract all GPS positions from an AVCHD video.
+exiftool -ee -p "$gpslatitude, $gpslongitude, $gpstimestamp" 'a.m2ts'
+
+# Recursively extract JPG images from Canon CRW files in the current directory.
+# Add 'C<_JFR.jpg>' to the name of the output JPG files.
+exiftool -b -JpgFromRaw -w '_JFR.jpg' -ext 'CRW' -r '.'
+```
+
+</details>
+
 ## Further readings
 
 - [Website]
 - [Github]
 
-## Sources
-
-All the references in the [further readings] section, plus the following:
+### Sources
 
 - [Top 5 ways to view and edit metadata]
 
 <!--
-  References
+  Reference
+  ═╬═Time══
   -->
 
 <!-- Upstream -->
 [github]: https://github.com/exiftool/exiftool
 [website]: https://exiftool.org/
 
-<!-- In-article sections -->
-[further readings]: #further-readings
-
 <!-- Others -->
 [top 5 ways to view and edit metadata]: https://daminion.net/articles/tips/top-5-ways-to-view-and-edit-metadata/
diff --git a/knowledge base/getfattr.md b/knowledge base/getfattr.md
index 98036c3..96bcca1 100644
--- a/knowledge base/getfattr.md	
+++ b/knowledge base/getfattr.md	
@@ -1,10 +1,8 @@
 # `getfattr`
 
-## Table of contents <!-- omit in toc -->
-
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
-1. [Sources](#sources)
+   1. [Sources](#sources)
 
 ## TL;DR
 
@@ -13,6 +11,9 @@
 apt install 'attr'
 dnf install 'attr'
 
+# Get values for all attributes.
+getfattr -d 'path/to/file.1' … 'path/to/file.N'
+
 # Get values for specific extended attributes.
 getfattr -n 'name' 'path/to/file.1' … 'path/to/file.N'
 ```
@@ -21,20 +22,16 @@ getfattr -n 'name' 'path/to/file.1' … 'path/to/file.N'
 
 - [`setfattr`][setfattr]
 
-## Sources
-
-All the references in the [further readings] section, plus the following:
+### Sources
 
 - [`man` page][man page]
 - [Tag files in GNU/Linux]
 
 <!--
-  References
+  Reference
+  ═╬═Time══
   -->
 
-<!-- In-article sections -->
-[further readings]: #further-readings
-
 <!-- Knowledge base -->
 [setfattr]: setfattr.md
 [tag files in gnu/linux]: tag%20files.md
diff --git a/knowledge base/touch.md b/knowledge base/touch.md
index ec623ab..1a6ff9b 100644
--- a/knowledge base/touch.md	
+++ b/knowledge base/touch.md	
@@ -1,7 +1,5 @@
 # The `touch` command
 
-## Table of contents <!-- omit in toc -->
-
 1. [TL;DR](#tldr)
 
 ## TL;DR
@@ -11,4 +9,14 @@
 # End the time with 'Z' to specify the new time is UTC instead of local time.
 touch -cd '2017-08-15T13:28:42' '20170815_132842.mp4'
 touch -cd '2017-08-15T12:28:42Z' '20170815_132842.mp4'
+
+# Change only the access time.
+touch -ca -t '201801211200.10' 'file.txt'
+touch -c --time=access -t '201801211200.10' 'file.txt'
+touch -c --time=atime -d '2018-01-21T12:00:10' 'file.txt'
+
+# Change only the modification time.
+touch -cm -t '201611161200.10' 'file.txt'
+touch -c --time=modify -t '201611161200.10' 'file.txt'
+touch -c --time=mtime -d '2016-11-16T12:00:10' 'file.txt'
 ```