On a Sharepoint 2010 server with the Document ID service activated I have a document library with content type management enabled. After adding a content type that I've created in Sharepoint Designer there are duplicates of the Document ID Generators as shown in the screenshot. I've also tried adding built-in content types such as video, or audio and I get the same behaviour.
My understanding was that aside from any custom event receivers there should only be four there. The four being ItemAdded, ItemUpdated, ItemCheckedIn, and ItemUncheckedOut. Is my understanding flawed?
Also, it doesn't appear to be a one-to-one correlation between number of content types and number of these receivers. On a different server there are document libraries with 50+ content types and 100+ event receivers. Checked on a fresh SharePoint 2013 server and the same issue is happening.