Decided to standardize on calling the SQL Similar To regular expression escape replaceable "escape" everywhere.
Instead of fully documenting the obsolete syntax I added a note explaining the keyword choice difference. Removed mention of it completely from the Pattern Matching portion of the documentation - that section has enough going on.
I also add "Same as" references for the two pairs of entries. Not married to them but they do seem warranted; having Pattern Matching be required reading to make that connection seems undesirable.