LODS, STOS, MOVS, INS and OUTS are all unconditional (doesn't matter which version of the prefix you use, but officially REP should be the same opcode as REPE).

LODS, STOS, MOVS, INS and OUTS are all unconditional (doesn't matter which version of the prefix you use, but officially REP should be the same opcode as REPE). SCAS is the one that scans for e.g. a nul byte.