Carry entered data into later steps
G221 says a multi-step process should not ask for the same information twice. It is the only sufficient technique W3C documents for 3.3.7 Redundant Entry, a Level A rule new in WCAG 2.2. The scope is wider than people assume. W3C covers information previously provided by the user or by the system, so a reference number, quote ID or application number generated at step one counts just as much as an address the reader typed. W3C's own examples turn on exactly that case. Two outcomes pass the test. The information is prepopulated into the fields, or it is displayed on the page where the reader can see it. Showing the value without refilling the field is enough, which matters where prefilling would be wrong.
How we find it in an audit
Our reviewers work through every multi-step flow and note each time they are asked for something already given. Checkouts, applications and booking flows are where it concentrates. System-generated values get the same check, since a reference number shown once at step one and demanded again at step four is exactly what this rule is about.
How affected users experience it
Retyping an address is a small annoyance for most people and a real cost for anyone whose typing is slow or effortful. For readers with cognitive disabilities and memory impairments it is worse than slow, because a reference number seen four steps ago has to be found again before it can be retyped. Carrying the value forward removes a step that never had a purpose.
Passes vs. fails
Passes
Step four shows 'Billing address, same as delivery' pre-checked, with the stored address displayed and editable for the exceptions.
Fails
A checkout collects the delivery address at step two, then presents an empty billing form at step four demanding the same address typed fresh.
This guide is our interpretation of W3C technique G221: Provide data from a previous step in a process. W3C publishes its techniques as guidance rather than as the standard, and says so on every one of them. The success criterion is what conformance is measured against, and a technique is one documented way to meet it.