Reply to comment

SYNC sets storage boundary alignment for the variable you are defining.  Firstly 01 and 77 level variables are always aligned on a double-word boundary (0, 8, 16, 24...) and level variable after the 01 begins on the next byte position, except if SYNC is specified.  A 9(4) COMP variable is aligned to the next half-word, a 9(8) COMP is aligned to the next full-word, and COMP-1/COMP-2 variables are aligned to the next double-word boundary.