# [MATL](https://esolangs.org/wiki/MATL), 18 bytes The current version ([4.0.0](https://github.com/lmendo/MATL/releases/tag/4.0.0)) of the language is used. This applies the same regular expression as [NinjaBearMonkey's answer](https://codegolf.stackexchange.com/a/67555/36398): j'^[A-Z][a-z]+$'XX The output is the string (which [is truthy](http://meta.codegolf.stackexchange.com/a/2194/36398)) if it's an official name, and nothing (which [is falsy](http://meta.codegolf.stackexchange.com/a/2194/36398)) if it's not. ### Examples >> matl > j'^[A-Z][a-z]+$'XX > > December December >> >> matl > j'^[A-Z][a-z]+$'XX > > ASCII >>