easydigitaldownloads/Easy-Digital-Downloads — pull request #2119 by mgibbs189 (2014-03-12 14:49:44+00:00)
Title: Add filter to ajax discount code

This allows for plugins to create discount "aliases", thus preventing the need to create tons of different discount posts.

Example use case:

A user enters their existing license key. A plugin could validate the license key and, if successful, replace it with the (existing) "RENEW" discount code.