Naming
Also said as Naming language, Phonotactics, Name generator
Naming people and places using a consistent set of sounds, so that they sound as if they come from one culture. The rules for which sounds can sit together are called phonotactics.
Players read a culture from its names before anything else. Random fantasy names sound like random fantasy names, and one small rule set makes two peoples sound different from one another.
Say it
“Build a naming language for the coast people: only soft consonants, syllables that end in a vowel or n, and 2 to 3 syllables. Every place and person on the coast gets named from that.”
Where you’ve seen it
The Elder Scrolls: Balmora, Sadrith Mora and Ald'ruhn in Morrowind sound like one people, and Whiterun, Windhelm and Riften in Skyrim like another. You can tell which province you are in by the sign.
Not to be confused with conlang
A naming language only needs sounds and a few word pieces, and it can be built in an afternoon. A conlang also has grammar and vocabulary, enough to write and speak in.