Jim;
Some answers:
S.5 CD&M School Woodstock Ont. = S5 Canadian Driving and Maintenance School, Woodstock, Ontario
4 CITU = No. 4 Canadian Infantry Training Unit
( 12 BM) CRRG or ( 12 BN) CBBG = No 12 Battalion, Canadian Base Reinforcement Group
X4 list = reinforcement
T.S. Coy = Trained Soldier Company
Furlough 14 Days , R/A $.50 = on authorized leave for 14 days and paid a ration allowance of $50.00
SOS TRG BDE GP to SER:294F Debert DO-107
SO .......................5 apr 44
TO ..........................6 apr 44 = he was stricken off strength of No. 1 Training Brigade Group (Derbert, N.S.) on 5 April 1944 and taken on strength of Serial 294F (his overseas draft) on 6 April 1944, which was probably the date he sailed from Halifax for the UK
Discembark ..............12apr 44
Reported for duty .....12apr 44 4 CITU = arrived in the UK on 12 April 1944 and reported to No. 4 Canadian Infantry Training Unit (same date)
21AGp = 21st Army Group (Second British Army and First Canadian Army made up this Army Group - hence - 21st Army Group)
A E F = Allied Expeditionary Force
21ALN = probably reads 21AGP (21 Army Group)
TOS from X4 list NSR(NB) unit-RRR place- 21AGp = taken on strength from the reinforcement list for the North Shore Regiment by the Regina Rifle Regiment, 21st Army Group
DO-25A., DO-107 etc = these are the numbers of the orders published that authorized each entry on his service record, I've forgotton off hand what the 'D.O.' stands for
Hope this helps.
Cheers