Error Identification
When a user input error is detected, the field in error must be identified and the error described to the user in text.
What it requires
WCAG 2.0 SC 3.3.1 requires that form errors be identified specifically — not "Some fields are invalid" but "Email field is invalid: please enter a valid email address". Errors must be available as text (not color-only or icon-only) so screen readers can announce them.
The accessibility-correct pattern: associate the error with the input via `aria-describedby` pointing at the error-message element, set `aria-invalid="true"` on the input, and announce errors in an `aria-live="assertive"` region.
Common Shopify failure
Checkout form turns invalid fields red but provides no text error message — screen-reader users have no idea what failed. Newsletter signup that says only "Error" with no detail. Custom shipping calculator that flashes a red border and silently exits.
How to fix it
AccessComply patches Liquid templates to render `<span class="error" aria-live="assertive">` next to each input, sets `aria-invalid` and `aria-describedby` correctly, and writes specific error text per validation rule.
Primary source: W3C — WCAG 2.0 Understanding 3.3.1