Need examples of relationships with information "on the arrow".

[Gary P Cole <Gary.P.Cole@Sun.COM>]

I need some help.  Participants in this morning's working group call 
debated whether SPML 2.0 needs to support what we term "complex" 
relationships:  relationships where the connection itself has attributes.

Our pet example of complex relationships is RACF Group Memberships.  In 
RACF, a user is not simply connected to a group.  In RACF, a user's 
connection to each group has attributes that apply to that connection.  
For example, a user can be SPECIAL (or NOSPECIAL), AUDITOR (or 
NOAUDITOR), OPERATIONS (or NOOPERATIONS), GRPACC (or NOGRPACC).  A user 
can also be REVOKED or RESUMED, either immediately or as of a specified 
date.  There are more options, but you get the idea.

It's been suggested that CA's Top Secret group memberships may be 
another example.  We hear that each Top Secret group membership can have 
an expiration date assigned to it.

Can anyone suggest another example of this kind of a relationship?  Any 
kind of relationship a customer might want to manage as part of 
provisioning is relevant, but I'll accept even far-out examples (since 
these might help to spur my imagination).

Thanks,

Gary