Best practice for WORM entities?

FROM : Stefan
DATE : Mon Aug 14 18:59:39 2006

I need to implement several entities, which need to follow the WORM 
principle -
write once, read many.

Does anybody has a pointer for the best location to define this 
property? Somewhere
in the model? In the GUI? Or do we have somewhere a flag to set the 
property

   'Can create and edit only once'.