While it is conforming to have multiple label elements pointing to a single control for labelling purposes, it is not recommended. It has been conforming as per (X)HTML specifications for many years, but it is not robustly supported. Other techniques such as wrapping the label around text and control and
aria-labelledby do the job better and are much better supported in modern browsers and assistive technology.
- Global Considerations in Creating an Organizational Web Accessibility Policy
- Short note on alt in HTML
- CVAA for Fostering Innovation and Change
- Usability and accessibility opportunities in a web component world