Bylaws are defined as "a set of legal rules adopted by the Board of Governors and ratified by a General Assembly or adopted by a General Assembly and ratified by the EUS Board of Governors for the governance of EUS legal affairs."
These are not to be mistaken with policies, which are documents that are guiding principles and best practices. Bylaws are legally binding, and therefore tend to be of more solidified and pertinent matters. Changing a bylaws requires a significant amount of work, including a General Assembly; if you're creating a document and wondering what it should be classified as, consider whether or not it's rules are settled for now and the distant future.
List of Bylaws
The EUSwiki currently only has the most up to date bylaws. If you'd like to see the repository of older edits and outdated bylaws you can navigate to the top-right link icon.