Accessibility Use Case Definition Language (UCDL) and Runner

This appendix is informative.

The Step Language inherits its core verbs (Locate, Gain Focus On, Enter, Select, Activate, Verify) from AFixt's manual use case testing methodology, refined over years of accessibility consulting engagements. This specification formalizes that methodology so that automated and manual testing produce comparable results against the same script.

Thanks to the Playwright team for an automation API that takes the accessibility tree as a first-class citizen, making accessibility-first targeting practical at scale.