Conventions
How to read the specification: shall, should and may, and which sections are informative.
How to read this document
shall is a requirement. should is a recommendation. may is a permission. Sections marked (informative) explain or give examples and are not requirements. Everything else is normative.
On this site
(Informative.) The three keywords are set in lowercase bold wherever they carry the meaning above, on every page and in the PDF. Each page of the specification carries a Normative or Informative tag; within a normative page, a heading or note marked (informative) is informative.
Section numbers are those of the PDF. Links to a section are pinned to the version they were written for, so a link to /v1.0/spec/core-code#grammar keeps pointing at the v1.0 text after later versions are published.
The Documentation and Adopt tabs explain the standard in plain words. They are informative: where they and the specification differ, the specification governs.