in what document of RUP should i put the Use case attributes (form fields)?

In what document of RUP should I put the Use case attributes (form fields)?

Suppose that there is a registration use case for some system. As a system analyst writing SRS开发者_运维问答, where could I write the specific attribute (form fields) of the registration use case? what is the name of this document?

Keep it simple and put that inside the same SRS.