Phonology, Phonotactics and Sandhi complete.
Phrase grammar complete.
CALS page complete.
Morphosyntax sketch complete. (question list from book of same name)
Swadesh (or alternative) list complete.
Core lexicon and derivational morphology complete to the point that most if not all words either exist or can be derived by a hypothetical speaker. In otherwords, the language community isn’t waiting for new words.
Intellectual property rules established, (i.e. released to public domain, CC, proprietary commercial licensing, etc)
Corpus, Community and Competency
Corpus (excluding pedagogical examples in reference grammars) has attested all or most lexical entries and grammatical structures.
1st translations of common texts, e.g. Babel text, Lord’s Prayer, Zompist Phrasebook, etc.
1st reported conversation (either on forums, online chat, voice chat or in person conversation)
1st period of sustained daily usage
1st successful in person gathering for the purpose of speaking in the language without code switching.
Milestones with significant economic barriers
Physical keyboards adapted for use with language
Unsubsidized books sales by someone other than the inventor, especially for non-pedagogical materials.
1st long format texts (novella, novel length)
1st podcast, talkshow, news program
Has language governance body with regular meetings.
Living Language Status
Organized in person communities with regular gatherings and activities (excluding pedagogical gatherings)
Language governance body documents what is happening more it than directs.
1st child to learn the language
1st 2nd generation child to learn the language
Spoken by extendend family. Individuals that marry into the family also learn the language.
Language use considered prestigious