These were worn by Officers of the 5th Battalion and are similar to the OSD collar (see bottom picture for a comparison of both collar badges). They are believed to have been worn on mess dress and are an unofficial badge.
They are almost half size of the normal 5th Battalion OSD collars and like the Service Dress collar badges, they are on loops.
There are some misrepresentations about these badges and how they came to be made. It has been suggested in a well known reference book that these were made in a small batch as a one off by Lt Col Parkinson in 1920. Records held in the York and Lancaster regimental archive show that the Commanding Officer of the 5th Battalion from 1920 through to 1927 was Lt Col S Rhodes and in fact, Lt Col Parkinson was during this time based at the Regimental Depot and then Commanding Officer of the 1st York and Lancaster.
It is therefore unlikely he would be in a position to influence the type of badges worn by a Territorial battalion. It should be noted that this myth is perpetuated by some badge dealers in order to secure a high price for similar badges that were fixed to souvenir picture frames.
(Also see the section on Fakes and Copies).