http://hl7-fhir.github.io/bundle-definitions.html#Bundle.entry.transaction.url

_Bundle.entry.transaction.url Definition A search URL for this resource that specifies how the resource is matched to an existing resource when processing a transaction (see transaction documentation). Control 1..1 Type uri _

This doesn't really make sense. If nothing else, "transaction documentation" should be a link. Bu tit would be good to say something like:

"URL to invoke, using the HTTP verb in entry.transaction.method, to perform a single operation in this transaction".

Similarly, other places in the detailed definitions that say "see x" (Search for "see" in http://hl7-fhir.github.io/bundle-definitions.html) should include hyperlinks.