Currently, html-aam states for <abbr> accname computation:

1. If the element has an aria-label or an aria-labelledby attribute the accessible name is to be calculated using the algorithm defined in Accessible Name and Description: Computation and API Mappings.
2. Otherwise use the title attribute.
3. If none of the above yield a usable text string there is no accessible name.

From quick testing of common AT/browser combinations with default verbosity settings (<abbr title="..."> test):

• iOS 18.6.2 & Safari = does not announce title
• macOS 15.6.1 & Safari = does not announce title
• JAWS 2025.2504.98 & Chrome 139.0.7258 = announces title
• NVDA 2025.2 & Firefox 142.0.1 = does not announce title

To investigate:

• Should title for <abbr> be exposed given verbosity concerns? See WebKit bug #145879 - AX: tag does not expose title= information to VO.
• If it were not exposed as accName, could it optionally map to accDescription when provided?