Maperitive, a desktop OSM renderer, stores its rulesets for rendering in a subfolder called "Rules" - at least when running under Windows.
I tried to generate my own rules (or to be more honest I changed a ruleset) and saved it under a new name like "myruleset.mrules" in this folder. Unfortunately, Maperitive does not seem to "recognize" new files in this subfolder "Rules". Restarting Maperitive does not help.
How can I "register" this new ruleset, so that it is available under the menu Map -> Switch to Rules?