How does one know if a derogatory term or phrase is reclaimed?

Does the term describe yourself? If not, you haven't reclaimed it.

If you have to ask, probably don't use it.

Language is constantly evolving. There is no clear line. New words are added, meanings change, and it depends on the intent of the speaker too.

However as a mater of practice I choose to never assume it has been reclaimed. It's always possible that someone hasn't received the update.

If you're not part of the group, then don't use it. I'd say maybe the only exception is "queer". I'm fine with people using queer to describe their friends and family who are queer. Not everyone is OK with it though, but it's pretty common. With queer, don't use it unless the person you're talking to self identifies as queer.

You don't.

As much as we might like to say terms can be reclaimed the judge of that is the listener... you need to comprehend how all the people you're talking to or who hear your words repeated will feel about it - just avoid derogatory terms.

Has that ever actually worked? Cause I know no examples of universally "reclaimed" words. Just some that are fine if you strictly use them to refer to yourself.

When you see someone write it on the back of their jacket and saying “it’s cool, we’re taking it back” whenever someone calls it out.

reclaimed or nullified?