the.com/bylaw

The rulebook a group writes so no one has to fight about rules later.

means A rule or regulation made by a local authority, company, club, or organization to govern its own members or affairs, rather than one handed down by a national government.

from Despite looking like it's built from 'by' + 'law' — suggesting some secondary, local law — the word actually traces back to Old Norse 'bylög,' from 'byr' (town, settlement) meaning 'town law.' It entered English via the Danelaw regions of England where Norse-speaking settlers governed their own towns. The modern spelling later got reshaped by folk etymology to look like it meant 'a law on the side,' which, charmingly, isn't far from the truth of how it's used today.

not optional
courts treat bylaws as legally binding, not suggestions
scope
governs internal affairs, from quorum to board elections
etymology trick
from Old Norse byr, meaning town, not just by meaning near
beats habit
written bylaw trumps tradition whenever the two collide
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