Audit the Selected Sample : Success Criteria to Evaluate

Dear Sir/Madam,

Due to my project on web accessibility, which I have cited and referred
your guideline and some information, I have queries that I would like to
ask for more understanding.
According to the link
https://www.w3.org/WAI/eval/report-tool/#/evaluation/audit Success criteria
to evaluate, there are 5 results on your page as: 'Not checked', 'Passed',
'Failed', 'Not present', and 'Cannot tell'. Could you please clarify on
each of the terms means, especially the 'Cannot tell'?

Thank you very much and I look forward to hearing from you.



Regards,

*Asst. Dr. Nattakant Utakrit*

Department of Technical Education Management
Faculty of Technical Education
King Mongkut's University of Technology North Bangkok