Line_SetIdentification — assigns an identifier to a line for scripting. Can also designate EAX environments.
Line_SetIdentification (lineid, bBoundary);
Line_SetIdentification ( lineid, // Identification number for this line bBoundary // Indicates if this line is a zone boundary );
This special must be placed directly on a line, because its primary purpose is to identify lines that can be altered with ACS. It performs no action of its own.
Zone boundaries are currently used only to designate areas for EAX environments. If you don't care about EAX, then you should set the bBoundary parameter to 0.
Assign this line an ID of 1:
ZDoom 2.0.43 added the bBoundary parameter