There are some activities in the game I just will never reach (i.e. PvP or some guild specific entries). I would like to add these single entries of the ALL THE THINGS list to an ignore list.
Entries on the ignore list will never appear in any list.

Adding to the ignore list could be achieved by ALT-clicking a row of the list.

Improvement:
List of ignored entries or filter option to see ignored entries to have a possibility to "unignore" them.

sorry, but there are not currently any plans to implement a "blacklist" feature in ATT!