TAXI INSTRUCTIONS.

Narrative

AFTER LNDG ON RWY 32 AND CLRING AT TXWY E; WE WERE INSTRUCTED BY GND CTL TO TURN R AND ENTER THE MAIN RAMP AT TXWY W. AS WE WERE TURNING N ON TXWY W WE WERE SWITCHED TO RAMP CTL; WHO THEN INSTRUCTED US TO TAXI TO THE GATE VIA TXWY YS. IT SHOULD BE NOTED THAT THIS WAS MY FIRST TIME EVER AT PIT; AND IT WAS ONLY MY FO'S SECOND TIME THERE; SO WE BOTH HAD OUR ARPT DIAGRAMS OUT AND WERE TRACKING OURSELVES FROM MAP TO REAL WORLD. AT THIS POINT WE WERE ENTERING THE MAIN RAMP AT TXWY W. TO OUR L FRONT WERE 2 ENTRANCES TO THE COMMUTER RAMP; LABELED Y1 AND Y2. SINCE I SAW NO TXWY ON THE ARPT DIAGRAM LABELED TXWY YS; I ASSUMED THAT SINCE Y2 WAS S OF Y1; THAT TXWY YS WAS SOME LCL SHORTHAND TERM FOR Y2. I PROCEEDED TO GATE VIA Y2 AND SHUT DOWN. AFTER PAX DEPLANING; I WAS INFORMED BY THE GATE AGENT THAT I MUST CALL RAMP CTL ON THE TELEPHONE. THE CTLR TOLD ME THAT I HAD DISREGARDED HIS INSTRUCTION AND 'CUT OUT' A TAXIING B737 ON THE MAIN RAMP (NEITHER I NOR MY FO SAW ANY B737). I INFORMED HIM THAT I WAS UNFAMILIAR WITH HIS NON-STANDARD TERM TXWY YS SINCE I HAD NEVER BEEN TO THIS ARPT BEFORE. THEY HAD WANTED ME TO ENTER THE RAMP VIA TXWY Y ON THE S SIDE OF THE RAMP (THIS WOULD HAVE REQUIRED ME TO DO A 180 DEG TURN ON TXWY W; AND DID NOT SEEM LOGICAL). LESSONS LEARNED: I SHOULD NOT HAVE ASSUMED THAT TXWY YS WAS Y2; THEY SHOULD NOT USE NON-STANDARD TERMINOLOGY.