Question about Regular or Extended License?

Hi guys.

One more question :slight_smile:
I read the information on https://themeforest.net/licenses/standard about Standard Licenses (Regular and Extended). But how can we manage this, on terms of sales?
For example someone buy me a regular licence script, which it modifies for its purposes, and put it on sale as another plugin or script.
Although the plugin or script might be changed with new features, shouldn’t the person who bought it for reselling, payed the Extended license rather than the Regular license?
How can we manage to prove that the plugin has been put it on sale with the Regular license, and how can we report similar situations? Sorry about all these questions.

Best regards.