Bug 245278 – AX: VoiceOver has no setting for sub/superscript announcement

• Component: Accessibility
• Status: NEW

[Adrian Roselli]

Created attachment 462396 [details]
The VoiceOver Utility in the Braille Status configuration pane.

### Summary

Subscript and superscript text is not audibly exposed. An example:

1. Go to https://cdpn.io/pen/debug/aGgBNZ in Safari with VoiceOver.
2. Read the content using any means.
3. Observe the sub- and super-script is not exposed in any way.
4. Look for a VoiceOver setting to expose it.
5. Find none.
6. Locate the VoiceOver Utility setting for Braille to show it (attached VO-utility.png) and enable "Show extended text style".
7. Using Braille viewer compare output with (VO-sub-sup_Braille-extended.png) and without (VO-sub-sup_Braille-default.png) that setting.

### Expected result

I expect to hear the sub- and super-script text as marked up by `<sub>` and `<sup>`.

Failing that, I expect there is at least a setting to allow VoiceOver to expose superscript and subscript text audibly to users.

### Actual result

The text was announced without denoting if it is sub- or super-script.

Both the `<sub>` and `<sup>` are mapped to the Apple-specific `superscript` and `subscript` roles in Safari, so this appears to be VO not conveying it.

The Braille viewer displays a blank cell after sub/superscript text when the "Show extended text style" setting is enabled, so it is being recognized there. Whether or not that is the correct way to denote sub/super is unknown to me, so there may be an issue there as well?

I found no other configuration settings that apply: https://www.apple.com/voiceover/info/guide/_1126.html

### Example

- Debug pen: https://cdpn.io/pen/debug/aGgBNZ
- Editable pen: https://codepen.io/aardrian/pen/aGgBNZ

Example HTML from the provided URL:
```
<sup>14</sup><sub>6</sub>C<sup>2+</sup><sub>8</sub>
```

### Additional Information

- NVDA has a setting (under Document Formatting) to announce sub- and super-script.
- As of the start of 2019 JAWS had no / dropped support for `<sup>` and `<sup>` (per https://freedomscientific.github.io/VFO-standards-support/html.html) so assuming that is still the case.
 
#### Operating System and version

- macOS 12.6

#### Browser and version:

- Safari 16 (the pre-configured version selector here only goes to Safari 15)

[Radar WebKit Bug Importer]

<rdar://problem/100030223>

[Adrian Roselli]

Created attachment 462397 [details]
Braille emulator showing the example with default settings.

[Adrian Roselli]

Created attachment 462398 [details]
Braille emulator showing the example with extended text style setting enabled.