R packages currently use a "Manual" bibtex type for what is essentially a pointer to a software landing page. We should have a think about how to support these kind of R citation blocks as something very akin to a software citation (e.g., have a version and a URL/PID). For instance in R manual package citations, the "note" field (deprecated in #53) is very much a "version" field. A couple of relevant threads to think about include:
The request in #53 to remove all uses of the URL key has negative outcomes for other types that almost entirely rely upon the URL keyword for including the URL in the references. Undo this outcome.
A few bst related fixes/improvements: