The letter T before the army number on the small pack straps indicates someone from the old Royal Army Service Corps. Their army numbers started with a T-. In fact they were REGIMENTAL numbers until just after the war, issued on a regimental basis until proper 8 figure ARMY numbering such as 23961234 (issued in Jan 63) started in the later 40's or so. Officer and WRAC (Womens Royal Army Corps) numbers were all 6 figure numbers such as 423665 (issued in 1964 or so). Now there's no difference. I think that they are now an 8 figure number starting several years ago at 30000000