The best replacement for bylaws is articles of incorporation.

The best alternatives to bylaws are rated as following:
★★★★★  articles of incorporation
★★★★★  operating agreement
★★★★★  constitution
★★★  policies
★★  charter
★★  covenants
★★  standing rules
★★  rules and regulations
★★  policy
★  articles of association
★  articles
★  policies and procedures
★  by-laws
★  by laws
★  bylaws
  shareholder agreement

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Speaking about bylaws, one probably shouldn't forget about being corporation.

Other search terms related to bylaws and their ratings are:

★★★★★ being corporation
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articles of incorporation
operating agreement