Reference

Structured reference data for Microsoft 365 admins — starting with a retirements tracker; more tables are added as they can be owner-verified.

Retirements trackerDated Microsoft 365 retirements and end-of-support deadlines already covered in this site's guides, plus an ICS calendar feed.
Admin portal directoryWhich admin portal manages what — deliberately shipped as a shell where the deep-link URL isn't yet owner-confirmed, rather than a guess.