same properties accross types

[mangar]

I feel as if I am missing a general idea here but, I want to have the same property applied to two different types. If I have a marketing doc and a legal doc (for example) and they both are say, part of the same campaign, why can't I add that property to both types?  I have a list of constraints of campaign names for that property, so how do i link the two together? 

I could make a super class, and maybe that's what Im supposed to do, but could someone explain why?

[invictus9]

The approach to use in Alfresco is to create an aspect. The aspect may have zero or more properties in it. You would define any common properties in the aspect. You would then make the aspect a required aspect of the base types.

[mangar]

Yes, that works great. however, could someone explain conceptually why this is?  Is this an aspect of Java and spring beans where properties are like classes and aspects are like interfaces?