Until 1916, regiments had organised their own training battalions back in the UK, which were then used to send men forward as replacements to frontline battalions of the same regiment in the field. This system was not without its problems however as recruitment was patchy across the country depending on population density, industry in a region taking precedence over army recruitment and the prestige of a regiment itself. Added to this, depending on the ebb and flow of battle, the actual requirements of a battalion in the field for replacements could vary wildly so one regiment might have men sitting in the UK waiting to be needed, whilst another might struggled to find replacements after a particularly bloody battle. In 1916 it was decided to centralise training into a series of training reserve battalions. The men would be trained outside the regimental structure and then sent forward to whichever regiment needed them (predictably the Guards remained outside this structure and continued as they always had!). The training reserve did not use regimental cap badges, but had a large general service button on a red felt disc as a unit cap badge and this symbol is to be found on today’s object, a training reserve pin badge:

Although the front looks exactly like a button, from the rear it can be seen that the whole badge is stamped from a single piece of brass, the ‘button’ being hollow behind, a broach fastening is fitted below:

This is one of a number of training reserve badges that can be found and it is unclear if they were sold as sweetheart badges or to identify those of the units when in mufti. It seems unlikely that any sweetheart would want to show affiliation to an administrative unit, having a boyfriend or husband serving in an active regiment was one thing, advertising he was attached to a training cadre quite another! A detailed history of the training reserve can be found here