'War Munition Volunteer' badge

Badges such as these were worn by civilians in order to indicate that the person wearing it was engaged in important war work.
Several of these badges were officially produced and distributed nationally, but many more were produced privately by companies to support their employees.

According to the Imperial War Museum : "Before conscription was introduced in 1916, the army relied on voluntary recruitment. It was assumed by many that a man not in uniform was avoiding joining up and was therefore often accused of shirking their duty to their country. The famous white feather campaign saw men not in uniform presented with a white feather as a symbol of cowardice.
The official badges were intended to prove that the wearer was doing their duty to their country in a time of war in a different way. They were not in uniform, but they may have been working in munitions factories or in the dockyards carrying out work that was vital to the war effort.
After conscription, the need for these badges faded, along with the white feather campaign. However, many continued to be worn throughout the war, especially by female shift workers for whom the badge could give priority boarding and fare concessions on public transport, as well as indicating that there was nothing disreputable about these ladies travelling alone at night".