ESA's governing documents consist of the following:
Bylaws [2]
Mission & Outcome Statements [3]
Ethics Statement [5]
Links:
[1] http://entsoc.org/about_esa/governance/documents/index.htm
[2] http://www.entsoc.org/PDF/about_esa/governance/documents/bylaws.pdf
[3] http://www.entsoc.org/about_esa/governance/documents/vision_mission
[4] http://www.entsoc.org/about_esa/esas-strategic-principles
[5] http://www.entsoc.org/about_esa/governance/documents/ethics