The Available up on Request role is a role which a project member in CollabNet TeamForge can submit a request for. You must be a site administrator or project administrator to create a Available upon Request role.
While creating global or project roles, you can select the Available upon Request option to allow the project member to see the role in Request Additional Roles section on the Project Home page.
When a project member requests a role, the request is submitted to the project administrator for approval. The project member receives an email notification when the request is either approved or denied.