This NIP is not yet in main. Here is an overview of PRs referencing this NIP. 
Add Twitter verification caveat to NIP-39. OPEN @ibz
Implement Markdownlint GitHub action OPEN @mariano-perez-rodriguez
Markdown improvements, embelishments, and standardizations CLOSED @mariano-perez-rodriguez
Update all NIPs to include 'depends' and 'mentions' tags OPEN @blakejakopovic
NIP-39 external identities in metadata MERGED @pseudozach
docs: add NIP-xx reposts CLOSED @Cameri