When the project is delivering its deliverables to its customer , a release audit is carried out by process team.
There will be a release audit checklist which needs to be checked for that particular release. If your company has QMS, am sure there will be a release audit checklist and please go through it.
You need to check if all the important project related artifacts are up to date, and if they are placed in a common repository. I mean CM tool like VSS, Clear case or SVN etc.
then You need to check if that deliverable . e.g. source code for some functionality is being released - if this has SRS, design doc, if the source code is well controlled in CM tool, if its reviewed, tested with test cases updated. Are the bugs / review comments tracked to closure? all these things needs to be checked. if any bug is not closed due to some reasons, has this been mentioned as a known issue in release note?
also, you can ask the team to run that particular functionality for you or you can also pick a test case and ask them to show the test results, and verify the same.
if no code reviews are carried out, or if the test coverage is not up to mark. and if the test cases fail [which they would have marked as pass] , you can reject the release of that deliverable and escalate it to the PM.
It depends on the project team to say what type of releases they want a release audit to be done. its mandatory for major released. ask them to inform you before they release, so that you can conduct the audit and if there are any observations they can close it before the release.
Tinkerbell's response is highly creditable.
Generally we have projects during project in progress and during those audits they raise lots of issues that need to be cared for, at the end when the project is closed, a release note is prepared. Release audit is done to check if the Process followed has been as is the company standard. Also in technical terms, it is a QUALITY Control phase by which the product quality can be maintained and the process followed by the QA team can be tracked.