Glossary
What are the Airman Certification Standards?
The FAA document listing every task, knowledge item and risk-management item a practical test can cover for a given certificate or rating, together with the tolerances a maneuver has to be flown within. It tells a candidate what they will be asked before they are asked it, and it replaced the older Practical Test Standards.
Also called ACS
That is the whole entry for now. The longer version, with the mechanics and worked examples, is still to be written. See autorotation for how those read once they exist.