Make deleted data recoverable
Deleting something does not have to mean losing it. G99 keeps deleted data recoverable, either by holding it somewhere for a while or by recording the deletion so it can be undone, and W3C counts it as sufficient for the error-prevention rule at Level AA. Two shapes do the job. A trash folder that keeps items for a set period before deleting them for real, and an edit history that can restore any earlier state, which is how wikis and version control handle the same problem. W3C also offers a confirmation prompt as a parallel route of equal standing. We prefer recovery, and that preference is ours rather than W3C's, because a confirmation dialog gets clicked through on reflex and a trash folder still works after the reflex.
How we find it in an audit
Anything that deletes gets tested by deleting something, then trying to get it back. First question is whether recovery exists at all. Second is whether the reader is told about it at the moment of deletion rather than in a help article somewhere, because a retention window nobody states is a promise nobody can rely on. Where the only protection is a confirmation dialog, we record which route the site took and note whether the dialog names what is about to go.
How affected users experience it
A misplaced keystroke costs more when you cannot see where it landed. A screen-reader user pressing Enter on the wrong list item. A switch user whose selection drifted a row. Someone with a tremor whose click went wide. Confirmation dialogs help less than they appear to, because a screen-reader user hears the dialog after the decision is already moving and the quickest way through it is Enter again. Recovery is the protection that survives all of that.
Passes vs. fails
Passes
Deleted drafts move to Trash for 30 days. The interface says so at the moment of deletion, and offers Undo on the spot.
Fails
A misdirected Enter on Delete draft destroys three hours of writing, instantly and permanently.
Other ways to satisfy this rule
7 guides on this site are filed under 3.3.4 Error Prevention (Legal, Financial, Data). W3C lists this one as sufficient for that rule on its own. Implement it correctly, in a way your readers' software actually supports, and the rule is met.
- G98sufficientLet users review answers before final submission
- G155sufficientAdd a confirmation checkbox before final submission
- G164sufficientState how long requests can be canceled
- G168sufficientAsk for confirmation before completing risky actions
- G199advisoryConfirm success when a submission works
- SCR18advisoryValidate in the browser and describe the error
This guide is our interpretation of W3C technique G99: Providing the ability to recover deleted information. 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.