Explaining forms

Hi,

I am trying to improve Topincs forms in such a way that a small  
explanation of the form field is offered. This becomes handy as soon  
as the field (statement) becomes more complicated, e.g. as recently  
shown in the newcomb number store [1].

Now i am wondering where to put this information in the topic map in  
such a way that it is possible to have a different explanation  
depending on the perspective of an association.

a. use tmcl:description occurrences on occurrence type and name type.  
make a custom occurrence type perspective description (scoped by role  
type and language) for association types
b. use tmcl:description occurrences on the constraints ((is it  
intended for this purpose?)
c. use a custom occurrence type on  the constraints

b and c additionally offer the advantage of being able to describe  
subject locator and subject identifier constraints, which not  
possible with a.

Currently I am in favor of c. Any thoughts or experiences?

Robert

[1] http://www.topincs.com/newcombnumber/