[Q] Codecanyon / ThemeForest / etc

What's the license / security system on Codecanyon, ThemeForest (and others) like?

XenForo Resource Leaker Identifier:

Allows you to scan readable files for variables such as [$user['id']] and replace it with their

user id xenforo.com/community/members/username.123/ (123) before the resource is sent to the user for download

Is there a system related to this on Codecanton/ThemeForest/or other popular resource sites that I should look out for, what are they and where can I find them? (for example in the url, user profile image link/identifier, or?)