Please add URLs that, when followed, lead to examples of diffs that rfcdiff handled poorly enough to justify work on improving it.
https://www.ietf.org/rfcdiff?url1=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fcharter-ietf-6man%2Fwithmilestones-03.txt&difftype=--html&submit=Go!&url2=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fcharter-ietf-6man%2Fwithmilestones-03-01.txt
https://www.ietf.org/rfcdiff?url1=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fcharter-ietf-mboned%2Fwithmilestones-03.txt&difftype=--html&submit=Go!&url2=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fcharter-ietf-mboned%2Fwithmilestones-03-02.txt
https://www.ietf.org/rfcdiff?url1=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fcharter-ietf-mif%2Fwithmilestones-03.txt&difftype=--html&submit=Go!&url2=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fcharter-ietf-mif%2Fwithmilestones-03-00.txt