This 2017 document from the World Wide Web Consortium’s Web Accessibility Initiative group describes steps to help you report website accessibility problems when you find them in the wild.
- Identify key contacts
- Describe the problem
- Follow-up as needed
The document also includes additional tips:
- Consider what approach will get the results you want
- Keep records of all communications for possible follow-up
- Encourage others to provide feedback to the organization
- Use sample emails provided in the document
Note that, although the advice this document contains is still relevant, it may occasionally refer and link to outdated standards due to its age.