There are no rules.
If you have a seedling, then it is new and unique, like your first born child, and thus has no name, and you get to do the honors.
Yours, having come from Carini probably had a name at one time. It may exist there, and here (brought by someone else) by its original name, or some other name (Luigi's Gold, or whatever). Since it is really hard to identify figs (they look different when grown in different places) you may never identify it. So, give it a name that preserves its past and is descriptive of what it is, and pass along the story of its origin when you share/sell cuttings. So call it Carini Black, or Fico Carini or some such name (I don't known what the color of this fig is). There are a ton of "Unknown Italian" figs, so give it a real name. Can't argue with just being honest about it when you are selling it. It would be nice if more people were.