Repeated-letter change
A word or phrase becomes another when one letter is changed to another letter wherever it appears (the letter must appear at least twice). Examples: monocle, manacle; or crochet, prophet.
A repeated-letter change may have more than two parts. Example: skunk, stunt, sauna; the same positions must have changed letters to form all other parts.
As is true of similar types (like the spoonergram, transposal, reversal, and letter-change), the repeated-letter change must work in both directions—that is, be
reversible. For example, puffy cannot be changed to puppy, because reversing the change would produce fuffy, not the original puffy.
The repeated-letter change was introduced by WILLz in 1980.