What the naming rules say — and what they don’t
Every character now carries two names: a first name and a surname. The pair, read together, has to be unique across your whole region — not just one server. That is why a name you held for twenty years may already belong to someone else, and why a good surname matters more than it used to.
Two names, one line in the register
Reported details describe letters, a capital first letter and lower case after it. Accents and a single internal apostrophe are reported as allowed; numbers and other symbols are not. These details still need in-game confirmation.
Twelve letters — of what?
The reported 2–12 limit does not settle whether it applies to each part or the combined pair. The checker shows both readings; neither is presented as confirmed.
Splitting a word doesn’t hide it
Blizzard says the system can evaluate both parts together. This checker also joins the two before checking its limited local list, but it cannot reproduce the game’s full filter.
When your name belongs to a legend
Names of well-known characters can be rejected, or changed later. The generator filters a small local list of them; the checker warns on those known entries, not on every name the game may refuse.
When the name is taken
Try the same name in a different hand: one accent, placed where it still reads cleanly. Your friends will still be able to find you.
Source: Blizzard’s official naming announcement for the two-part system, regional uniqueness and joint filtering. Length and format details remain reported until client verification.