By this date, all features with updates to be landed in main for the release must be named and acked by the [http://launchpad.net/~ubuntu-release gruppo di rilascio]. Having this freeze gives them a chance to identify any features which should be subject to an earlier [:../PartnerUploadDeadline:NewPackageUploadDeadline] or [:../FeatureFreeze:FeatureFreeze] deadline because they are especially risky.