In the CHK format description for triggers: http://www.starcraftai.com/wiki/CHK_Format#.22TRIG.22_-_Triggers,

there is an unsigned 16 bit integer:


I am creating a tool to generate triggers directly into TRIG format. Do I need to worry about this field or can I just keep it at 0 or whatever default value it is?

I've never used that field, and I just leave it at 0

EUDX Trigger which added in SC:R, uses last 2 bytes of condition/action (0x12, 0x13 for condition, 0x1E, 0x1F for action) for EUDX symbol, which is 'SC'.