An identifiable revision of a quote, including the commercial details relevant to a decision. It lets everyone identify the exact proposal being discussed, rather than relying on a filename or an old message.
An example
The finance reviewer approves quote v3 at S$105,000 with annual billing. Quote v4 adds quarterly billing. The team checks the approval rules again because the earlier decision did not necessarily cover the new schedule.
What to check
A version reference should let a reviewer recover the actual content. An approval should not silently transfer to material changes.
In practice
Show what changed and which previous decisions still apply. Keep superseded versions available for context while making the current version obvious to reviewers and the account team.