It negotiates a series of Minimum Terms Agreements governing writers' contracts and covering minimum fees, advances, repeat fees, royalties and residuals, rights, credits, number of drafts, script alterations and the resolution of disputes. The most important MTAs cover: BBC TV Drama; BBC Radio Drama; ITV Companies; PACT (independent TV and film producers); TAC (Welsh language independent TV producers); Theatrical Management Association; Independent Theatre Council; and an agreement covering the Royal National Theatre, Royal Shakespeare Company and Royal Court Theatre. These agreements are regularly renegotiated and in most cases the minimum fees are reviewed annually.