A document people must read and confirm — your proof of required reading, per person and per revision.
A must-read is a document with an obligation attached: the assigned people must read it and confirm they did. Think procedures, work instructions, safety policy.
You assign a must-read by role, so everyone who must know it gets it automatically — new colleagues included. The confirmation is recorded with a name and a moment.
When the document changes, the new revision supersedes the old one and you choose whether everyone confirms again. You always know who knows the version that applies now.