The following is a list of all the variables used on the system and in what cases (pages, parts of the system) they are used. The list is almost complete and will be updated while the variables are updated to their specific scopes:


PAGE TYPE COMMON VARIABLES USED ON THIS PAGE TYPE
content $w
data_post $w, $user, $post
data_category $w, $dc, $profs
account $w, $user
payment $w, $subscription
profile $w, $user, $subscription, $profession, $service
SYSTEM ARRAYS
USAGE
$w (Used on all pages)
$s (Membership Feature Specialty)
$r (Membership Feature Reviews)
$p (Membership Feature Photo Album / Classifieds)
$g (Similar to $group)
$post (Membership Features)
$user (Used where single user data appears like Member Profile)
$user_data (Used where there is multiple user data like Search Results)
$profs (Brings filters like country, state, zipcode, top level, sub level...) eg: Search Results
$data_results (Search Results)
$dc (Everything related to categories)
$page (Everything related to current page)
$group (Everything related to Groups like Group Photo Album)
$photo (Everything related to Photos)
$subscription (Everything related to Subscription)
$profession (Everything related to Profession Level and Information related to it)
$service (Everything related to services by either members or membership features)
$lead (Everything related to leads in the system or members)
$review (Everything related to the review process)
$label (Used on all Pages for labels used on the Text Labels sections)
$_COOKIE (HTTP Cookie Data)
$_SERVER (Information about the Server)
$_REQUEST (HTTP Request Data)
$_FILES (HTTP File Uploaded Data)
$_GET (HTTP GET Data)


Here is a detailed video that shows how to use these variables.