If you have work experience you didn't originally mention or claim Comprehensive Ranking System (CRS) points for, and you want to add it to your personal history section after receiving your Invitation to Apply (ITA):
- It's generally fine to add it, as long as you are not claiming any CRS points for that experience — the group's consensus was this shouldn't trigger an Additional Document Request (ADR) on its own.
- No proof/documentation is required for personal history entries in general — job certificates or similar supporting documents are not needed just to list a period of work in your personal history.
- Personal history records are treated as a factual record of your history, not something you need to substantiate with attached evidence, according to the group's shared understanding.
Bottom line: you can add previously unmentioned, unclaimed work experience to your personal history without needing a job certificate, and doing so shouldn't by itself prompt an ADR.