I have attempted to classify the types of Order of St John Service Medals which I don't think has been done, or at least published, previously. I have identified 6 distinctly different types as in the first image below. The second image shows Types 4/5 and Type 6. It is difficult to distinguish between the post war Types 4 & 5 because they are not officially engraved although many, especially Type 4, were engraved by local HQs. Type 4 also appear to have a matt, or less shiny, finish. There may be some overlaps - for example in 1923-25 between Types 1 & 2; or with the mounting on Types 5 & 6. I'd also like to identify more precisely the numbering of Types 2 & 3 and in particular when the numbering first started. Do please get in touch if you can help. I hope this more precise classification will help date and identify these medals in the future but help in finalising the table will be very welcome!