[Correct errors] - New Requirement needed- Error description / error message / error suggestion should be easy to understand

[RashmiKatakwar]

Under Correct Errors, a new requirement should be added stating that error descriptions,
error messages, and error suggestions must be written in plain language and be easy for
users to understand.

Proposed requirement

Error descriptions / error messages / error suggestions:

• Must use plain language — avoid technical jargon, system codes, or abstract phrasing
• Must be easy to understand — the user should immediately know what went wrong and
  what to do next
• Must not be vague — messages that leave the user guessing do not meet this requirement

Failure example (real world)

Scenario: A form requires the user to check an "I am not a robot" checkbox before
submitting.

What happens: The user submits without checking the checkbox.

Error message shown: "Only humans are allowed to submit this form."

Why this fails:

• The message does not tell the user what action they missed (checking the checkbox)
• It does not tell the user how to fix the error
• A user unfamiliar with CAPTCHA conventions may not connect this message to any specific
  field or action on the form
• The phrasing is ambiguous and potentially confusing for users with cognitive disabilities

A plain language alternative would be:
"Please check the 'I am not a robot' checkbox to continue."

[detlevhfischer]

This does not seem substantially different from Error suggestions provided: Error messages include suggestions for corrections. Whether the actual language in the message is clear and simple should be covered by a general requirement under 2.2.3 Clear language.
.