Crossword clues for Envelope abbreviation 3 lettersAnswerClueENCEnvelope abbreviationAVEEnvelope abbreviationAPOEnvelope abbreviation.RDIAbbreviation on an envelopeESQAbbreviation on an envelopeRFDAbbreviation on an envelope.PERSEnvelope abbreviation.ATTNEnvelope abbreviationATTNBusiness-envelope abbreviationATTNAbbreviation on many business envelopes