ID exists presently, may be changed later.
Either waiting for further information/evidence, confirmation or a period of time to elapse before upgrading. It'll probably move to Solved - Best Name Available but do not quote me.
Think of it like Bon Jovi. We're halfway there.
It's also a good marker for people to search for and revisit. Hence provisional.
In this example we have a name but nothing that backs it up concretely. It's been around for five months, so we'll revisit it accordingly or when new evidence is supplied