Most Cotonti scripts run in the global scope as it is historically built this way. Some variables are common enough to be seen in many places around the code. This article covers the most important globals.
Note: this guide comes handy for theme developers as well. You can use any of these global variables as global template tags as well. Just remember the CoTemplate syntax. E.g. $usr['profile']['user_avatar'] in a template becomes {PHP.usr.profile.user_avatar}.
Cot facade class
There are some...