This option causes A-Shell to emulate some of the more restrictive characteristics of AMOS that are not always wanted. (The presumed motivation would be to prevent you from getting too comfortable with bypassing such limitations, making it difficult to port back to AMOS.) As of Build 791, the only example of this is the "protection violation" error you get when trying to write to a file outside your project. (Since neither Windows nor UNIX has any such arbitrary restriction, A-Shell normally ignores it.) But if you want to a "protection violation" whenever you attempt to write outside your project, then set OPTIONS=STRICT.