The first significant document in Williams service record is the ‘Short Service Attestation Army Form B 2512 a google search on ‘Army form B2512’ led me to a very useful explanatory document on:

‘gordonhighlanders.carolynmorrisey.com/Recruitment.htm’

From this information I worked out that the form was introduced under the Derby or Group scheme a last effort to raise voluntary recruits before conscription was brought in. The number 6 entered in the Card No box refers to group 6, men born between 1889 and 1892. The men were put on the reserve list and called up by group at a later date. My Grandad attested on the 9^th of December 1915, but wasn’t mobilised until the 15^th of June 1916.