Before you do a final publish for delivery, release all topics in the publication and freeze the baseline.
Releasing the topics When doing a final publish for delivery, releasing all the topics in the publication first, allows for a publishing status result of Release Candidate for the publication. Only when the publication is a Release Candidate you can release and freeze the publication.
Releasing the publication output When you have a Release Candidate for an output format for a publication version, it can be released for distribution to your customer base.
Freezing the Baseline Once all of the content is released, you can freeze the baseline of a publication. You only freeze a publication when no additional changes are needed to the contents. By freezing a baseline, it is always possible to know which version of each object was used for the publication.