Thanks.
I see, now, how the whole "Add Topic" function works; if your thread isn't posted in a forum that contains a specific topic, you cannot add that topic to the thread. Being in General/Chat, the topics available are listed here:
http://www.freerepublic.com/focus/f-chat/topics
But that list isn't the same as the topic list available for News/Activism threads:
http://www.freerepublic.com/focus/f-news/topics
Look at both pages and compare the items under "General Interest". "Vanity" is listed as a News/Activism topic, but not a "General/Chat" topic, so it cannot be added to this thread. OTOH, I was able to add "Miscellaneous" because it appears in both lists.
Maybe what's most confusing about this is that the "Topics" link on the FR homepage doesn't navigate to a "master list" of topics, but links to the "News/Activism" topics list, instead, which are only applicable to threads poted in "News/Activism".
BKM (sorry for the corporatespeak) is to navigate to the "Forums" page, and pick the "topics" link displayed to the right of the forum in which the thread is posted to which you want topics added. Then, all of the topics on the displayed list will be valid for the thread you're targeting.
Yes, it depends on which master list you're under.
Browse by Forum
Bloggers & Personal
General/Chat
GOP Club
News/Activism
Religion
RLC Liberty Caucus
Smoky Backroom
VetsCoR
I have my forum page set to 'All of the above' so I get to see everything. If you pick one then hit the "Post Article" link at the top, you can then see which topics that thread will list by hitting the button next to "Topics". You have to select one to four for the News forum; not sure that you have to in the others.