This directory contains “informal specifications”.
In order to move faster and get better feedback, we implement and iterate on language changes before the full official specification has been written. Still, the implementers need something to go on.
For that, the language team writes “informal specifications”. These are intended to be precise enough for a good faith implementer to correctly understand the syntax and semantics of the language, but without all of the laborious detail of the complete specification.
Once the feature has been implemented, tested, and we are confident in it, the language team will write the real text in the language specification and the document here becomes deprecated and no longer canonical.
Until then, while the feature is in progress, a live pull request for the informal spec is the source of truth for the feature.