I was reading an older Microsystems article announcing of the 68000 and it included this passage when describing the instruction set:
String. STRING MOVE, STRING SEARCH; and TRANSLATE are specified but not implemented in the first version.
Given the names, they appear to be intended to be similar to the PDP-11's CIS string instructions - I assume TRANSLATE, for instance, uses a 256-entry table to map from one charset to the other, while move would copy N bytes from address A to address B.
I don't recall any such instructions, so I found the Sun assembler manual for the 68020 and can't find any trace. Did these simply get left at the roadside, or did they eventually appear later in the series?
The 68000 programmer's reference manual, which covers the 68k family up to the 68040 and dates from 1992, uses the word 'string' on only four pages:
FMOVE, i.e. decimals packed into strings;The 68060 user's manual again refers to packed decimal strings in the context of FMOVE but otherwise doesn't make reference to them outside of some code listings.
Therefore I would conclude that the 68k family never acquired string move, search or translate.