Non-deterministic order of and elements in XML. See https://sources.debian.net/src/qtbase-opensource-src/latest/src/tools/qdoc/helpprojectwriter.cpp/?hl=630#L787 etc.
Our notes about issues affecting packages are stored in notes.git and are targeted at packages in Debian in 'unstable/amd64' (unless they say otherwise).