Edit distance
Also: Levenshtein distance
The number of single-character insertions, deletions or substitutions needed to turn one string into another, used to measure how close a domain is to a brand.
Distance 1 is conservative and distance 2 is thorough and noisier. For a brand under five characters, distance 2 surfaces unrelated words that share letters by coincidence, which is why short brands should start at 1.