Attached to this blog post are two pieces of content that should help you as you try out the new enhancements to Datum Feature Symbols (aka Datum Tags) in Creo 4.0.
Any questions or feedback you have related to Datum Feature Symbols should be provided as comments to the blog post.
That will be the easiest way for me to keep track of the comments and also be able to provide timely responses to your questions. If you follow this post, you can be notified of those comments as well and be able to learn from what others are asking. I may also periodically update this post to add some new details or information related to Datum Feature Symbols.