I have tried to find a list of all environment variables in the InDesign OM, alas, without success. I have already stumbled on the following.
Even in the wonderful Jongware's Object Model (Adobe InDesign CS5 (7.0) Object Model JS: Table of Contents) there is no information on this.
I am just looking for the reference library that contains these values. I have no specific scripting task in mind.
Any help much appreciated!