Clarifications to the wheel specification

[pradyunsg (Pradyun Gedam)]

Major.

Require packing wheels without files in the root directory

Skipping the terminology question… If we want to add functionality to the wheel format, we need a new major version bump. If we want to remove functionality from the wheel format, we need a minor version bump. So far, this is the only proposed change that I’ve seen to remove functionality from the format.