Validation rules

The five rules an ovrin tag can carry and the eight formats they accept, what each one checks, and what a value is normalised to when it passes.

Ovrin validates extracted fields against the rules implied by the schema and tag grammar. This is the main safeguard that prevents bad output from flowing silently downstream.

Examples of rules

  • required
  • enum
  • min
  • max
  • format-specific constraints
  • cross-field rules

Why they matter

These rules are how the library turns vague extracted text into something that can be trusted in business logic or sent to a ledger or compliance workflow.