meta-refresh-no-exceptions
Page must not use a timed meta refresh (AAA)
Checks that <meta http-equiv="refresh"> does not set a positive delay, however long; an immediate redirect (delay 0) passes. This is the stricter AAA-level counterpart of the A-level check, which exempts delays over 20 hours.
Applies to. Applies to the first <meta http-equiv="refresh"> element, in document order, with a valid content attribute, per HTML's shared declarative refresh steps, a document only ever acts on its first valid meta refresh, so a later one (valid or not) is inert and out of scope.
Expectation. Running the shared declarative refresh steps against that element's content value results in a delay of exactly 0. An immediate (delay=0) redirect still passes at AAA, same as the A-level rule. There is nothing for a user to be interrupted mid-read by when nothing is displayed first. Any positive delay fails, with none of the A-level rule's >20-hour exemption: at AAA, WCAG 2.2.4 (Interruptions) and 3.2.5 (Change on Request) require that a timed automatic context change happen only at the user's request, regardless of how long the timer is.
Examples
<meta http-equiv="refresh" content="0; URL=/x">
A delay of exactly 0 is an immediate redirect; there's nothing to interrupt a user mid-read.
<meta http-equiv="refresh" content="30; URL=/x">
At AAA, any positive delay fails, with no exemption for a long delay.