Difference between pages "File:Fqi-009.png" and "Template:Shell/Doc"

Example 1:

{{shell
| Desc = Descriptiontext
| Input = # command to run
Output of command<br>
<font color=#ff0000;>Alert!</font>
}}

Will produce:

and Example 2:

{{shell
| Input = # command to run
Output of command<br>
<font color=#ff0000;>Alert!</font>
}}

Will produce:

and Example 3:

{{shell
| Desc =
| Input = # command to run
Output of command<br>
<font color=#ff0000;>Alert!</font>
}}

Will produce:

Please be aware if you are using | inside the Input String it wouldn't work and break you need to replace | with | and inside the input it is saver to use clean HTML code. :)