Versio Enactionis
The rule, in the Medium edition of the Gibsonian canons, that every law is pinned to the version of the interpretive canons in force when it was enacted, so that later changes to the canons cannot silently change its meaning.
First used in Version Control for Law
The rule is dependency pinning applied to interpretation. A software project pins the version of each library it depends on, so an upstream update cannot break it without notice. Versio Enactionis does the same for interpretive method: a statute enacted under one set of rules is read under those rules, not under whatever rules are current when a dispute arises.
A related canon, Relatio Certa, freezes incorporations by reference at enactment unless they are explicitly dynamic, so a change in an upstream document cannot rewrite downstream law.
Together the two address silent drift: a change in legal meaning that happens without any amendment to the text and without anyone having decided it.
Related terms
Related frameworks
Version Control for Law
Legal interpretation can be governed like a versioned codebase: enacted text is the protected main branch, opinions are signed commits, dissents are preserved branches, and overruling is a force push allowed only through logged, gated conditions.
The Gibsonian Canons of Constitutional Interpretation
A closed, priority-ordered law of interpretation, enacted before any institution is given power to interpret, that binds every interpreter to the same method and requires a traceable record of each interpretation.