3.3.2 Labels or Instructions
Description of this issue:
Input fields should always have a description that is explicitly associated with the field to make sure that users of assistive technologies will also know what the field is for.
How to fix it:
If the input field has a visible description indicating the purpose of the field, this description should be explicitly associated to the input field either as a HTML label or using the WAI-ARIA attribute ‘aria-labelledby’.
If it is not possible to add a visible description, either add a mouseover text (‘title’ attribute) to the input field or create an invisible label using the WAI-ARIA attribute ‘aria-label’.