Information and the operation of the user interface must be understandable. This principle covers readable text, predictable behavior, and input assistance.
Guideline 3.1: Readable
3.1.1 Language of Page Level A
The default language of each page must be programmatically determinable via the lang attribute on the <html> element. Crucible Scan verifies the lang attribute exists and contains a valid language code.
How to fix: In WordPress, go to Settings → General and set the Site Language. WordPress automatically sets the lang attribute accordingly.
3.1.2 Language of Parts Level AA
Content in a different language than the page default must have its language identified using the lang attribute on the containing element.
Guideline 3.2: Predictable
3.2.1 On Focus Level A
Receiving focus must not initiate a change of context (e.g., submitting a form or opening a new window).
3.2.2 On Input Level A
Changing a form control setting must not automatically cause a context change unless the user was warned.
3.2.3 Consistent Navigation Level AA
Navigation mechanisms repeated across pages must appear in the same relative order.
3.2.4 Consistent Identification Level AA
Components with the same functionality must be identified consistently across pages.
3.2.6 Consistent Help Level A
Help mechanisms must appear in the same relative order on each page when repeated.
Guideline 3.3: Input Assistance
3.3.1 Error Identification Level A
Input errors must be identified and described to the user in text.
3.3.2 Labels or Instructions Level A
Labels or instructions must be provided when content requires user input. Crucible Scan checks for form inputs without associated labels.
3.3.3 Error Suggestion Level AA
If an input error is detected and suggestions are known, they must be provided to the user.
3.3.4 Error Prevention (Legal, Financial) Level AA
Submissions involving legal commitments or financial transactions must be reversible, checked, or confirmed.
3.3.7 Redundant Entry Level A
Information previously entered must be auto-populated or selectable rather than requiring re-entry.
3.3.8 Accessible Authentication Level AA
Authentication processes must not require cognitive function tests unless an alternative method is available.