The table below maps the accessibility checks implemented in AccessODF to relevant success criteria in the Web Content Accessibility Guidelines (WCAG) 2.0 and to the Authoring Techniques for Accessible Office Documents by the ADOD project (version 3.2, dated February 2011). In addition to general accessibility checks, AccessODF can perform checks that are applicable only to Braille or to DAISY digital talking books. Some checks do not map to any WCAG 2.0 success criterion. Version 0.1.0 of AccessODF only checks word processing documents supported by Writer, in other words, it does not check the accessibility of spreadsheets or presentations.
In the table below, the WCAG 2.0 success criteria are at Level A, unless mentioned otherwise. Readers can follow the links to find out more about each success criterion.
| WCAG 2.0 | ODF Check(s) | Comments |
|---|---|---|
| 1.1.1 Non-text Content | Error: formula has no text alternative.
Warnings: image has no text alternative; object has no text alternative; special characters or symbols are rendered by means of a special font instead of Unicode. |
ADOD Technique 3.
Some images may be decorative and therefore not require a text alternative. |
| 1.3.1 Info and Relationships | Warnings: table contains merged cells; table cell contains another table; table has no repeatable heading row(s); table rows break across pages or columns; table is very long; long table has caption below table instead of above; caption is not linked to any image or table; text formatting (e.g. big bold text) suggests that a paragraph should have a Heading style. | ADOD Technique 6 (using named styles instead of
direct formatting).
ADOD Techniques 7.1, 7.2, 7.3, 7.4. |
| 1.3.2 Meaningful Sequence | Not tested. | Requires research on the effect of floating objects and frames on reading order. |
| 1.3.3 Sensory Characteristics | Not tested. | ADOD Technique 9.4. |
| 1.4.1 Use of Color | Not tested. | ADOD Technique 8 (in charts).
ADOD Technique 9.3. |
| 1.4.2 Audio Control | Not tested. | |
| 1.4.3 Contrast (Minimum) (AA) | Error: contrast between foreground text and background is too low. | ADOD Technique 9.2. |
| 1.4.4 Resize text (AA) | No test required. | Writer has built-in zoom functionality. |
| 1.4.5 Images of Text (AA) | Not tested. | ADOD Technique 9.5. |
| 1.4.6 Contrast (Enhanced) (AAA) | (See success criterion 1.4.3.) | |
| 1.4.7 Low or No Background Audio (AAA) | Not applicable. | Writer documents can embed audio but not as background sound. |
| 1.4.8 Visual Presentation (AAA) | Warnings: text is justified; font size is smaller than 9 points; long span of text in all caps, underlined or italic. | ADOD Technique 9.1
WCAG does not require a minimum font size or prohibit text that is in all caps, underlined or italic. |
| 1.4.9 Images of Text (No Exception) (AAA) | (See success criterion 1.4.5.) | |
| 2.1.1 Keyboard | Warning: An image anchor is not set to “As Character”. | ADOD Technique 4. |
| 2.1.2 No Keyboard Trap | Not tested/no test required. | Unless macros can trap the keyboard, this needs to be handled by Writer. |
| 2.1.3 Keyboard (No Exception) (AAA) | (See success criterion 2.1.1.) | |
| 2.2.1 Timing Adjustable | Not applicable. | Not applicable, unless macros can create time limits. |
| 2.2.2 Pause, Stop, Hide | Not tested, except blinking text. | |
| 2.2.3 No Timing (AAA) | Not applicable. | |
| 2.2.4 Interruptions (AAA) | Not applicable. | |
| 2.2.5 Re-authenticating (AAA) | Not applicable. | |
| 2.3.1 Three Flashes or Below Threshold | Not tested. | |
| 2.3.2 Three Flashes (AAA) | Not tested. | |
| 2.4.1 Bypass Blocks | Not applicable. | |
| 2.4.2 Page Titled | Errors: document has more than one Title style; document has an empty
Title style.
Warnings: document has no Title style; paragraph below Title is formatted in a way that suggests it should have a Subtitle style. |
Some documents may not require a title, e.g. letters. |
| 2.4.3 Focus Order | Not tested/not applicable. | Writer is an editing environment, and pressing TAB has a different effect than navigation in a browser. |
| 2.4.4 Link Purpose (In Context) | Warning: hyperlink text is identical to hyperlink URL. | ADOD Technique 10.2. |
| 2.4.5 Multiple Ways (AA) | Warning: Braille edition has no table of contents. | ADOD Techniques 7.5, 7.6. |
| 2.4.6 Headings and Labels (AA) | Errors: empty Heading style; incorrectly ordered headings; heading
inside a frame (DAISY check).
Warnings: document contains no Heading styles; document has more than 6 levels of headings (DAISY). |
ADOD Technique 5.
Some documents may not require headings, e.g. letters. |
| 2.4.7 Focus Visible (AA) | Not tested. | |
| 2.4.8 Location (AAA) | Not applicable. | |
| 2.4.9 Link Purpose (Link Only) (AAA) | (See success criterion 2.4.4.) | |
| 2.4.10 Section Headings (AAA) | (See success criterion 2.4.6.) | |
| 3.1.1 Language of Page | Error: document has no default language | ADOD Technique 2. |
| 3.1.2 Language of Parts (AA) | Errors: span of text has no language; a hyperlink has no language.
Warning: paragraph has no identification. |
ADOD Technique 2.
In Writer, hyperlinks have no language unless the author specifies one (or modifies the character style “Internet Link”). |
| 3.1.3 Unusual Words (AAA) | Not tested. | |
| 3.1.4 Abbreviations (AAA) | Not tested. | Writer does not have a built-in style or mechanism for abbreviated forms. |
| 3.1.5 Reading Level (AAA) | Not tested. | ADOD Technique 10.1.
Algorithms to evaluate reading level are language dependent. |
| 3.1.6 Pronunciation (AAA) | No test required. | Relevant to DAISY export. Unclear how this can be addressed in Writer. |
| 4.1.1 Parsing | Not tested. | Writer takes care of well-formed XML internally. |
| 4.1.2 Name, Role, Value | Not tested. | ADOD Technique 6 (using named styles facilitates mapping to roles). |
Some WCAG 2.0 success criteria are not mentioned in the above table:
- The success criteria for time-based media (audio, video) under Guideline 1.2 (i.e. success criteria 1.2.1 to 1.2.5): these success criteria are usually irrelevant to word processing documents. They may be relevant to presentations with embedded audio or video.
- The success criteria for predictable behaviour of web pages under Guideline 3.2.
- The success criteria for input assistance (forms and context-sensitive help) under Guideline 3.3. These criteria are relevant to documents that contain forms. Creating forms in Writer is possible, but more research is needed on creating accessible forms with LibreOffice or Apache OpenOffice.org.
The following warnings implemented in AccessODF do not correspond to any success criterion in WCAG 2.0:
- The document contains images in a format not supported by DAISY.
- An empty title field in the document properties (useful for DAISY or PDF export).
- The document contains a form (form accessibility in ODF requires more research).
- Material will be omitted in the Braille edition because it is not placed in any volume, supplement or preliminary section.
- Material is omitted in the Braille edition because odt2braille is unable to process it.
- In Braille, material is transposed from its original location. This warns the author that lists, text boxes and images inside a table rendered outside the table in the Braille version.
- A volume doesn't start at a logical place. Volumes should begin with a heading. (A warning specific to Braille.)
- The document contains 8-dot Braille but the file format (for Braille export) does not support it. (Printed Braille typically uses 6 dots, but printed 8-dot Braille also exists.)
- The document contains 8-dot Braille but the embosser does not support it.