- expands on what's needed for "faked" controls inside a disabled
<fieldset> - centralises the accessibility advice about always providing an accessible name, and mentions some of the possible variants; includes strong suggestion not to rely on placeholder and invisible labels as beyond AT users it can be bad for other user groups
- updated warning about validation, which (due to #28414), is actually worse than the (now improved) browser default validation; expanded the example for server-side to explicitly tie error messages to form fields using
aria-describedby
this should at least partially be backported (manually, since v4 doesn't have the overview page)