Thanks for the suggestion. So you think it should be a note that says:
If you add validation attributes through LLBLGen Designer's "Additional Attributes" feature, make sure the Release Configuration of the generated project is set to generate pdb files. This is required if you plan to use it in a RIA client library Project or Silverlight Business Applications, otherwise your generated entity code will be missing your custom attributes.
Do you have some article or help link that supports that note?