IGS (file format)
From GICLWiki
Extension: .igs
System: Initial Graphics Exchange Specification(IGES)
Description: ASCII File, may contain electrical data
Extension: IGS
Program and/or Extension Function: CAD Overlay
Specific Notes: CAD overlay 4.1-7.2 releases 12&13 and S8 release 14.
Identifying Characters: (None or Unknown)
Program ID: (None or Unknown)
General Notes: This entry has not yet been verified by FILExt. It was submitted to the list and appeared to be accurate; however, no verification links have so far been found on the Internet. Please use this association data with that in mind.