Semantics of capabilities in property descriptions

When a producer declares that a given property is required (via 
capability wsrp:required), is it valid for a consumer to not supply a 
value. There may be use cases where the consumer cannot simply supply a 
value.

The current wording in the spec is as follows:

wsrp:required: This capability means that the user has to supply a value 
for this property. If this capability is not set, the user of the 
property may choose whether or not to supply a value.

The intent of this wording (particularly the second sentence) is not 
very clear to me. I presume the term "user" means the "sender" of the 
property.

(BTW, the term "capability" in this context seems a bit awkward.)

Comments?

Subbu