Accessibility Metadata Viewer

Validating records

The metadata viewer provides validation of accessibility metadata to help users locate issues that might be affecting the statements that get generated.

The validator cannot be used to verify the overall validity of an EPUB package document or ONIX records. General validation issues are outside the scope of this application.

The application will only identify the following common problems:

• missing required or recommended properties from the EPUB Accessibility standard;
• duplicate value declarations (e.g., the same accessibility feature specified twice);
• unknown value declarations (i.e., that are not in the schema.org vocabulary);
• multiple values are not declared where only one is expected;
• non-standard spelling of values (e.g., "aria" instead of "ARIA");
• invalid mixing of values (e.g., declaring accessibility hazards or features are "unknown" alongside known hazards or features);
• invalid or incomplete mixing of accessibility declarations (for ONIX records only);
• invalid email addresses (for contact email);
• unknown properties in the a11y: namespace.

The validator will also report XML errors in the records. Note that unlike traditional XML processors these errors do not halt the validator; the JavaScript processor will repair the broken XML allowing validation to continue.