A or feature ID (though WALS features currently only go up to 144). 📘 Potential Sources
A in a digital library or Mendeley/Zotero collection.
Most likely refers to the World Atlas of Language Structures , a large database of structural properties of languages.
The phrase appears to be a specific citation or reference key, likely from a bibliography or a linguistic database. While "WALS" commonly refers to the World Atlas of Language Structures , this exact string is not a standard chapter or feature title in the main WALS database.