Records of the Black Theatre Forum (ref. BTF) are held at
Future Histories - Black Performance and Carnival Archive.  The online catalogue describes the collection as follows:  
"[t]he archive material dates from the late 1970s to the late 1990s. It consists of the Black Theatre Seasons records - including scripts, publicity material, leaflets, posters, press cuttings, photographs, audiotapes / soundcues from some productions - and relative correspondence, financial documents and minutes of meetings. The collection also includes: business records of the organisation; information on conferences, black cultural events, workshops and projects organised by BTF and other black organisations; publicity and information on various black theatre companies; newspaper cuttings on black theatre from mid 1970s to 1990 and a considerable number of theatre manuscripts. 95% of the archive is paper based, generally A4 sized. There are also photographs and a few reel-to-reel and cassette audiotapes."

'Open access to archive. Some files are closed due to data protection and conservation reasons.'  (Source: online catalogue)

Online catalogue.