Comment by almata

Just to mention one that's usually quite ignored, I love the simplicity and usefulness of the Levenshtein distance: https://xlinux.nist.gov/dads/HTML/Levenshtein.html

I once implemented it in typical scenario where sales people had to look for a client, but it could be written as: 1/ That Client With A Strange Name, Ltd. 2/ The Client With Strange Name, Ltd. 3/ That Client With A Strange Name 4/ [etc]

It worked really well and avoided lots of duplicated entries.