COPIED CLRNC AND READBACK; 'CLEARED INTO POSITION AND HOLD'. TRANSMISSION MEANT FOR ANOTHER ACFT.

Narrative

I WAS CLRED INTO 'POSITION AND HOLD' ON 30R AND READ BACK THE CLRNC TO THE TWR. A FEW SECONDS LATER WHILE TAXIING INTO POSITION AT THE APCH END OF THE RWY; THE TWR ASKED 'ARE YOU WITH ME?' MY REPLY WAS 'AFFIRMATIVE; POSITION AND HOLD.' THE TWR THEN CLRED ANOTHER ACFT INTO POSITION APPROX 2000' DOWN THE RWY (FROM AN INTERSECTION). THAT ACFT WAS CLRED FOR TKOF AND ANOTHER ACFT WAS CLRED TO LAND ON 30R. THE TWR'S NEXT XMISSION WAS FOR ME TO 'HOLD SHORT'. I WASTED NO TIME EXITING THE RWY AND ADVISED THE TWR I WAS CLRED INTO POSITION BUT UNDERSTOOD NOW TO HOLD SHORT. WITHOUT FURTHER COMMENT I WAS CLRED FOR TKOF AFTER THE LNDG TFC. THE TWR MAY HAVE BEEN AWARE OF MY POSITION ON THE RWY AND SIMPLY RAN OUT OF TIME TO CLEAR ME FOR TKOF. BUT BECAUSE OF THE CLRNC TO 'HOLD SHORT' RATHER THAN TO TAXI CLEAR OF THE RWY AND HOLD SHORT; I'M NOT SURE THE TWR WAS AWARE OF THE FACT THAT I WAS IN POSITION ON THE RWY. THE TWR OBVIOUSLY DID NOT HEAR MY ACKNOWLEDGEMENT OF THE INITIAL CLRNC TO 'POSITION AND HOLD' AND I DON'T KNOW IF THEY HEARD MY REPLY WHEN ASKED 'ARE YOU WITH ME?' THE TWR CTLR WAS VERY BUSY SO I DIDN'T DISCUSS THIS QUESTION WITH HIM.