I would like to know if there is a list of rules regarding the syntax for custom commands in X-Plane. I am asking because recently, a commercial provider generated custom commands for their product and they contain spaces and special characters (+, -). They do not work as intended and some of us users think that is because of the spaces and/or special characters. After creating a ticket with the provider they challenged my assertion that spaces are not "allowed" in custom commands and are therefore the reason their custom commands do not work. I searched around but couldn't find any published rules.
Many thanks for any pointers to the rules!