3
The issue cascades through all modules.
Posts that were previously identified by a full display name in 2.2.x e.g. John Smith of ABC Co. are now identified by the username that was set by the member at registration, can contain no spaces, and might be anything at all.
This can be combated by a setting in CBB3.08 with a preference to show the realname of the member in the post.
Optimism is the mother of disappointment.