R12 Required Descriptive Flexfield (DFF)

We have several DFFs setup in our 11.5.10.2 instance on vendor sites.  If a clerk sets up a new site and forgets to fill in the DFFs a message will pop up reminding them and will then take them there.

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In our R12 test instance I see the DFFs listed but there is nothing that requires they be filled in.  Is there a White Paper or Note that will tell me how to make the DFFs required once again in R12?

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Thanks in advance...