According to the AMO’s third-party library usage policy, only release versions of such libraries are permitted. An AMO reviewer elaborated further when they rejected a new release of my Firefox add-on:
Please note that only stable releases are acceptable (not beta, pre, RC, dev etc).
I am using the rdflib.js library for processing user-generated RDF/XML data files that were created in the XUL+XPCOM legacy versions of my add-on. (The rejection of my add-on was not because of this library, but another one which was indeed in beta.) The version of rdflib.js that I am using is numbered 0.16.2. Would this version be considered a “release” version?
On another note, the latest version of this library won’t process the RDF/XML files from my add-on because the way the RDF XPCOM modules generated RDF data isn’t compliant with the library’s requirements. Removing this library from my add-on will mean removing the ability for many of my users to import their old RDF/XML data files, which is problematic considering that my add-on has been around since Firefox 1.0.