This NIP is not yet in main. Here is an overview of PRs referencing this NIP.
NIP-09: Add `a` tag deletion MERGED @pablof7z
Minor JSON fix MERGED @AsaiToshiya
Add "z" as authorized deletion pubkey tag OPEN @arthurfranca
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
Minor typos and a correction to NIP-09 reference to pubkey MERGED @vasil9v
stronger wording for relay deletion behavior MERGED @khimaros