I'm dealing with a clerk in a Military District Archive Office for someone... they want a Foglio Matricolare of a grandparent.
He was surprised that the clerk needed his grandfather's date of birth, he couldn't understand what it had to do with the Military service record. I then began to wonder if the explanation that I sent him may be useful to post here... Here it is:
A quick insight into the importance of the 'birth year'....
When your grandparent was born he would have been said to be
'Of the class of 1883'.
This tradition continues even today. The date of birth is always shown on the Foglio Matricolare as that is the date from which the boy's military service calculations will be made. So we know that if the 'draft' age was 20 then he would becalled to report for military service just before his 20th birthday. This will also be recorded on his 'Foglio'. At that point he would probably undergo medicals and his personal details would be recorded too (height, weight, colour of eyes, hair etc). Then he would be sent home to await allocation, after a short time, to a regiment. That would be recorded too...
So his original Foglio Matricolare will be added to as and when things changed in his military service - each being carefully recorded. The final part of this would be his 'Congedo Assoluto' which are his final discharge papers and which he, and the Comune, can use to prove that he has met his military obligations in full.
Below is a link to an Image Shack copy of a Foglio Matricolare for someone born in December 1894. If you look on the third part it starts by saying
"Conscription soldier of the Class of '94 Girgenti District"
The next line says:
"Given unlimited leave on 23 June 1914" (so he was 19y 6m)
"Called to arms and joined 11 September 1914" (this is when he was allocated to, and joined his regiment)
The 'key' to this document is indeed the date of birth...