Rhapsody's RY_LICENSE_FILE environment variable

As ex-Telelogic stable mates' both Rational Rhapsody and Rational DOORS use FLEXlm licensing. They share the use of the TELELOGIC_LICENSE_FILE semi-colon separated environment variable. How to set up license is quite well documented but did you know there is also an RY_LICENSE_FILE environment variable? The logic? Well perhaps you want Rhapsody token licenses to be pulled from a different license server than DOORS? Actually, I also found at one point Rhapsody was pulling license servers from a registry entry at one point also! At least nowadays you can see the license path being pulled from in the About Rhapsody dialog.