May I be pedantic and point out that Pvt. Lancaster was not one of the dead of Passchendaele, but died in the First Battle of Ypres, trying to arrest the German advace across Belgium, in 1914. The Battle of Passchendaele was part of the Third Battle of Ypres in 1917.

Private Lancaster was a 'regular reservist', and having served time in the regular forces was recalled to the Army in August 1914, during the 'reserve' period of his 12 year enlistment*.

Walrus.

"...At the Going down of the Sun, and in the morning
We WILL remember them..."


* A Soldier generally enlisted for 12 years service, that is a fixed period** in the regular forces and the balance to be served as a reservist, subject to a number of training weekends per year (2 or 3 IIRC) and liable for immediate recall 'to the colours' as required.

** Subject to arm of service, theatre of service and some other factors.