BartVB
but IMHO this should be limited to listings of a specific forum, not of a list of all topics on the site.
I asked myself the same question regarding pinned topics that are only interesting for a certain tag, e.g. an admin message with tag-specific rules. I came up with the following solution:
I created an additional tag with the only purpose to hide these topics from the All discussions
view. In the admin panel I checked the Hide from All Discussions
option in the settings for this tag. Because this tag doesn't serve any other purpose, I disallowed creating new topics with this tag (except for admins), then I used CSS to hide this tag label wherever it showed.
The only side effect is, that these tag-specific pinned discussions don't show up at all in the All discussions
view, but that's OK for me.