As with any piece of legislation its doesnt specify the type, SSSTS and SMSTS are both forms that are more widely accepted.

apoligies for the poor phrasing, thank you for your input MrH&S

EXDEEPS, i am very surprised at our comment, if u googled SMSTS, Site manager Safety Training Scheme, can u guess SSSTS??? Mr H&S

MrH&S - Like ExDeeps I didn't know what the initials in your subject heading meant and I guess that most other forum users outside the construction sector wouldn't know either. It's good advice for anyone posting on this forum not to rely on initials and acronyms alone unless they're widely known ones. If anyone's in doubt about what is widely known, it's best to give the words or titles in full followed by the initials or acronyms in brackets. After that, using the initials or acronyms is good for brevity and ease of reading. Also, after seeing your riposte to ExDeeps I tried googling the two sets of initials in your thread headings: For SSTS I found 51 alternative suggestions, including subsurface sewage treatment system and Scandinavian Student Travel Service but none which seemed to be immediately relevant to OS&H. As for SSST, there were 37 suggestions including single stool sample test (furniture-related?) and Short Scottish Secure Tenancy (presumably 'Short' refers to tenancy duration rather than the height of the tenant!), but none which had clear OS&H connections! Thus, searching the internet does not necessarily provide reliable results, even if considerable and scarce time is spent on searches. :-(