A320 DEP FROM RWY 4R AT BOS ENTERED RWY AFTER CONFUSION REGARDING HOLD LINE LOCATIONS AND ATC CLRNC RECEIVED.

Narrative

AT BOSTON; I WAS ISSUED THE CLRNC TO TAXI TO RWY 4R. AFTER ARRIVING AT THE RWY 4R HOLD SHORT LINE; I SET THE PARKING BRAKE AND AWAITING FURTHER INSTRUCTIONS; ANTICIPATING BEING ISSUED A TKOF CLRNC. I WAS THEN ISSUED THE CLRNC TO PROCEED 'TO THE VISUAL HOLD POINT.' AFTER CLRING THE SHORT FINAL APCH COURSE; I PROCEEDED ONTO THE RWY TO THE VISUAL HOLD POINT WHERE THERE USED TO BE A SIGN TO THE L OF THE RWY INDICATING THE POINT TO WHICH ACFT SHOULD TAXI UP TO IN ORDER TO BEGIN THE TKOF RUN. I COULD NOT SPOT THAT SIGN AS IT WAS UNLIT. I SET THE PARKING BRAKE WHILE IN THE TKOF POS AND A FEW SECONDS LATER I RECEIVED A TKOF CLRNC. FIRST OFF; THE SIGN ON THE RWY (IF IT IS STILL THERE) SHOULD'VE BEEN LIT. IF THE SIGN IS NO LONGER THERE; THE CLRNC TO 'PROCEED TO THE VISUAL HOLD POINT' IS VERY DECEIVING IN THAT IT LEADS AN ACFT (WHILE ALREADY HOLDING SHORT OF THE RWY) TO SOME POINT ON THE ACTUAL RWY SURFACE SINCE THAT IS THE NEXT ANTICIPATED COMMAND AWAITED FROM THE TWR. AFTER SPEAKING WITH THE TWR CTLR; WHO ADVISED ME THAT MOST ACFT CONFUSE THE ILS HOLD SHORT LINE AS THE RWY HOLD SHORT LINE AND THAT'S WHY THEY ISSUE THE 'PROCEED TO THE VISUAL HOLD POINT' LANGUAGE. MY CONCERN IS RWY INCURSIONS AND HOW THE COMMAND TO 'PROCEED TO THE VISUAL HOLD POINT' LEADS A PLT ALREADY HOLDING SHORT OF THE RWY TO ANOTHER POINT ON THE RWY SURFACE WHICH MAY OR MAY NOT BE LIT OR STILL AN ACTIVE POINT.