Project Server undocumented reserved keyword

I work with Microsoft Project Server 2010 and found that there are some undocumented limitations. We needed to add a new ECF (Enterprise Custom Field) and named it to ParentProjectUID. This should work without any problem, but it does not! I think it is a reserved keyword for future usage or because of the [dbo].[MSP_EpmInternalProjectHierarchies] table which has a column called ParentProjectUID. Repro steps: Create an ECF custom field and name it to ParentProjectUID.  create... [More]