Global variables

Is it there any list or doc where I can spot what the system global variables are (i.e. USERID, COMPANYNAME, etc.)? Could variables like these (application scope, not object scope)be created, edited and accessed? Any help will be greatly appreciated-- Greetings, Paul.

Hit F5 in the Object Designer for the C/AL Symbol Menu and scroll down in the leftmost window to SYSTEM. The middle and righmost windows will then show you an overview of the system-related variables/functions available. You can use these in the usual way. USERID, COMPANYNAME and the like are, however, not related to the system, but to the current database, so for these variables you need to scroll down a bit further to DATABASE. Note that this kind of information is read-only, no adding or editing. John