How To Remove Items From "Dock"

If it's not self-evident, you'll have to ask. Before asking -- search. This question has been answered a great number of times.

https://trisquel.info/en/forum/how-remove-unwanted-app-launchers-panel

Since Trisquel is based on Ubuntu, most answers from Askubuntu are useful.

https://askubuntu.com/questions/77260/how-to-remove-a-launcher-from-a-gnome-panel#77266

Gnome Org has documentation of its own. The problem is, Trisquel uses Flashback and Gnome Panel thus retaining some features deprecated in the official Gnome 3 specifications. You're not supposed to add apps to your panel in Gnome. We'll have to rely on our community support when we stick to old ways or deviate from the mainstream.

Gnome 3:

https://wiki.gnome.org/Gnome3CheatSheet

https://help.gnome.org/about/

This is really old:

https://people.gnome.org/~bmsmith/user-guide.pdf

Trisquel documentation is here:

https://trisquel.info/en/wiki/documentation

It's a Wiki that you can edit and contribute to.

The answer to your question is here:

https://trisquel.info/en/wiki/managing-panel-launchers

It's usually called a 'taskbar' because it behaves like the taskbar in Windows. Officially it's a panel. A dock would be something 'afloat' or 'Mac-esque'. There are docks for Linux, such as Awn, Avant, Cairo or Docky.

Maybe it's an appropriate time to bring this up as a reminder. You should not take it personally. It was written by Eric S. Raymond so read it with a grain of salt.

http://www.catb.org/esr/faqs/smart-questions.html#before

I'm not a hacker so I don't mind answering any questions that are asked sincerely. I've got all the time in the world. In the process of looking for answers I might learn something myself.