Standards in the warez scene are defined by groups of people who have been involved in its activities for several years and have established connections to large groups. These people form a committee, which creates drafts for approval of the large groups. In organized warez distribution, all releases must follow these predefined standards to become accepted material. The standards committee usually cycles several drafts and finally decides which is best suited for the purpose, and then releases the draft for approval. Once the draft has been signed by several bigger groups, it becomes ratified and accepted as the current standard. There are separate standards for each category of releases.
An overview of these rules can be found here