CRJ CREW TAXIED PAST HOLD LINE; SHORT OF RWY.

Narrative

AFTER COMPLETING DEICE PROC ON DEICE RAMP; RECEIVED CLRNC FROM DEICE RAMP CTL TO TAXI VIA TXWY J; HOLD SHORT OF TXWY A; CONTACT GND ON TXWY J. SHORTLY AFTER ENTERING TXWY J; I NOTED WHAT APPEARED TO BE A CAT II HOLD SHORT SIGN. WITH EXCELLENT VFR CONDITIONS; I KNEW CAT II OPS WERE NOT IN USE; SO I CONTINUED TAXIING ON TXWY J. AS I APCHED THE SIGN FOR THE HOLD SHORT LINE; IT BECAME APPARENT THAT IT WAS IN FACT A 'CAT I' RWY 28 HOLD SHORT LINE. WE TAXIED PAST THE LINE FOR SEVERAL FT BEFORE BRINGING THE ACFT TO A COMPLETE STOP. DORVAL GND NOTIFIED US THAT WE HAD PASSED THE HOLD SHORT LINE. WE MENTIONED THAT THE CLRNC WE HAD GOTTEN WAS TO TAXI ON TXWY J; HOLD SHORT OF TXWY A. REVIEWING THE TAXI CHART; REVEALS THE HOLD SHORT LINE IS ROUGHLY 1200 FT SHORT OF THE RWY; 1000 FT SHORT OF TXWY A. VISUAL APCHS WERE BEING CONDUCTED TO RWYS 24; NO APCHS WERE BEING FLOWN TO RWY 28. NO CONFLICT WITH TFC TAXIING; ARRIVING; OR DEPARTING WAS NOTED. I BELIEVE THE UNUSUALLY LARGE DISTANCE FROM THE HOLD SHORT LINE TO THE RWY; AND THE AMBIGUOUS CLRNC BY DEICE RAMP CTL; BOTH CONTRIBUTED TO MY MISINTERP OF THE HOLD SHORT LINE. PERHAPS MORE DESCRIPTIVE SIGNAGE; AND A NOTE OR SYMBOL ON THE TAXI CHART; WOULD HAVE BEEN EFFECTIVE IN ALLOWING US TO PLAN FOR THE HOLD SHORT LINE SOONER.