Im in australia so it's a bit different down here
Most horses will carry the stud brand on the left shoulder, and the foaling details on the right. The foaling details are two numbers, one above the other.
The top number is the foal number (i.e. "2" for the second foal branded witht he stud brand that year) and the bottom number is the year (single digit) I.e. 2001 becomes "1" - but "1" may mean 1991 or 2011 (go off horse's teeth obviously)
Some studs (not common these days, perhaps a fashion trend?) will place the numbers up on the neck but the stud brand usually remains on the opposite shoulder :)
My current horse has shoulder brands, my last arab had the stud brand on the shoulder, and the foal details on his neck - all the horses from his studd had it done that way
Goodluck with your fact finding mission :)