Comment 1 for bug 496823

If @b is a subtag of @a, task Z will show up on @a's task list, so tagging it @a only serves to mark it with @a's color. I suppose I've done this manually: for example, one of my parent tags is colored dark blue, and its children are other shades of blue.

I typically treat parent tags as just a container for subtags. I don't tag any tasks with the parent tags, except in cases when the task goes in that general category but doesn't deserve its own subtag. That is, I use them more like hierarchical folders than tagging with both parent tag and child.

My one slight concern with this proposal is that it would create an inconsistent behavior with the other ways of adding tags, since adding @b in the task editor does not automatically add @a.