About the scene:
The scene rules

The scene rules are the standards in the warez scene for releasing warez. These standards are the minimum requirements for a release. The scene rules 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. The scene rules can be updated anytime, though it is most likely that the rules won't change more than 1 or 2 times a year.

Why these rules?
The scene rules may seem a little strict, but they certainly are not there to bother rippers. There are several reasons why these rules exist:

1. The rules enforce high quality releases only, so no worries about bad quality, error or other bad stuff.

2. Because the releases are divided into small parts you don't have to worry about re-downloading the whole release if something goes wrong. You can control that everything has been downloaded correctly by checking against the SFV-file. Hence you will always know whether you've gotten a complete uncorrupt release of what you were downloading.
This means that you will have the exact same files on your computer, when you've downloaded and extracted the release, as the person who first ripped the movie and created the release.

3. The rules lead to a standarized way of sharing, which the downloads obviously benefits greatly from. You will learn to recognize a good release and be spared the inconvenient trouble/surprise of poorly ripped movies by amatures. Also it's much easier to compare releases to eachother.

4. Scene releases always contain all the information about how it's ripped, what the quality is etc. This way you always know what you're downloading.

You can find rulesets etc. here.