CONFUSING LANGUAGE OF REVISED SEGMENT OF PDC RESULTS IN TRACK DEVIATION AT ARR ARPT FOR A319 FLT CREW.

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LATEST ATIS CALLED FOR RWY 36L/R FOR LNDG RWYS. WE WERE TOLD TO EXPECT RWY 18R FOR LNDG. APCHING CLT VIA THE UNARM ARR; CLT APCH CTL ASKED IF WE WERE MAKING A L TURN NORTHBOUND. WE HAD BEEN FLYING THE UNARM ARR. AT THIS TIME A TURN N WAS REQUESTED WITHOUT ANY TFC CONFLICT. REMAINDER OF DSCNT; APCH AND LNDG WERE ROUTINE. ORIGINAL FILED WAS CRLNC WAS...'GRD ADENA 1 CLT.' AT GATE IN ZZZ A REVISED SEGMENT WAS ISSUED 'GRD UNARM.' FLT CREW SAW UNARM AND INCORRECTLY ASSUMED UNARM 1 ARR. BOTH ADENA 1 AND UNARM 1 ARRIVALS OVERFLY UNARM INTXN. AFTER LNDG A REVIEW OF THE REVISED SEGMENT WAS STUDIED TO DETERMINE WHERE THE CONFUSION LAY. IT WAS THE 'UNARM' THAT LED THE CREW TO MISTAKE THE ARR. THE ADENA 1 ARR WAS THE CORRECT ROUTING. CLOSER ATTENTION TO THIS DETAIL WILL BE NECESSARY IN FUTURE. IN RETROSPECT; WHY IS 'UNARM' LISTED AS A REVISED SEGMENT? ADENA 1 AND UNARM 1 STARS BOTH OVERFLY UNARM! A REVISED SEGMENT OF 'GRD UNARM' IS REDUNDANT. NOTHING IS DIFFERENT A POTENTIAL MISTAKE IS IN THE MAKING; AS EVIDENCED BY OUR ACTIONS. THERE IS PROBABLY A REASONABLE EXPLANATION FOR IT; BUT FROM A PLT'S PERSPECTIVE IT IS QUITE A COMMON PRESENTATION TO HAVE A 'REVISED SEGMENT' THAT IS REALLY NO DIFFERENT THAN FILED.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT; OF THE POTENTIAL MISINTERPRETATIONS POSSIBLE; THEY CHOSE THE WORST. ASSUMING THEY HAD RECEIVED A 'REVISED' CLRNC VIA THE UNARM STAR CAUSED THEM TO NOT BE CONCERNED PASSING UNARM. HAD THEY CONSIDERED UNARM A CLRNC LIMIT THEY WOULD CERTAINLY HAVE QUERIED APCH CTL FOR FURTHER CLRNC PRIOR TO ENTERING A HOLD. THEY WOULD HAVE RECEIVED CLARIFICATION AND A TRACK DEVIATION WOULD NOT HAVE OCCURRED. AS IT WAS; THE TRACK DEVIATION HAD TO TAKE PLACE BEFORE ANYONE WAS AWARE OF THE MISINTERPRETATION. RPTR REITERATED THAT; HAD NOT THE REVISED SEGMENT BEEN PRINTED IN THE FIRST PLACE; NEITHER WOULD HAVE BEEN A POSSIBILITY. FOR THE SIMPLE REASON THAT THE STATEMENT REVISED NOTHING EXCEPT THE ABILITY TO BE CLEARLY UNDERSTOOD AND EASILY MISINTERPRETED.