It seems that there is a clear instruction about the programme notes for DipABRSM (official guide).
According to the Trinity diploma syllabus,
There should be a concise note on each piece, focusing on its context, content and significance. A useful guide to the kind of approach looked for may be taken from professional public concert programmes.
Timings for each work or movement should be included. Your notes should avoid lengthy biographical detail and/or generalisations about composers and styles. Plagiarism should be avoided
What do I need to include, or must not include, in my ATCL programme notes? For example, DipABRSM does not allow appearance of candidate name in the programme notes.