About notability: Arka is a artlang which has an a priori conculture and an a priori conclimate which were made from scratch. There are two books published in Arka and Japanese (see below). And there is an Arka community in Japan. An Arka fan teaches the language at his site, he also sells a textbook on Arka at Comic Market. Another fan of translates Arka into Japanese and makes fonts, he's even in the process of making an original shooter game here. There are secondary sources on Arka and it is a well-known conlang in Japan. See also: The official site and An outline of Arka in English