B737 FLC CROSSES HOLD SHORT LINE OF RWY 19L AT MCI AND STOPS.

Narrative

WHILE TAXIING FOR TKOF; RWY 19L AT MCI; TWR CTLR CLRED US 'INTO POS AND HOLD RWY 19L.' WHILE TAXIING ONTO THE RWY; I NOTICED WHAT APPEARED TO BE A COMMUTER JET ON ABOUT A 2-3 MI FINAL. I STOPPED APPROX 10-15 FT OVER THE RWY HOLD SHORT LINE AND ASKED THE FO TO QUERY THE TWR CTLR ABOUT OUR CLRNC 'ON TO HOLD.' THE TWR CTLR DID NOT RESPOND TO THIS REQUEST; BUT THE ACFT ON FINAL XMITTED THAT HE WAS LNDG ON RWY 19L. THE TWR CTLR RESPONDED TO OUR SECOND QUERY WITH 'CLRED FOR IMMEDIATE TKOF RWY 19L.' WE ADVISED HIM WE WOULD BE 'UNABLE' AND THAT WE WERE 10-15 FT OVER THE HOLD LINE. TWR THEN HAD THE SHORT FINAL ACFT GO AROUND. SINCE THERE WAS CONFUSION ON OUR PART AS TO WHETHER OR NOT THE TWR CTLR REALIZED HE HAD AN ACFT ON A SHORT FINAL; I WOULD RECOMMEND THAT HIS INITIAL XMISSION INCLUDE THE TFC ON FINAL WHILE CLRING US 'INTO POS AND HOLD.' (IE: 'TFC ON 4 NM FINAL; CLRED INTO POS AND HOLD'). THE COMMUTER JET I THOUGHT I SAW ON ABOUT A 2 NM FINAL TURNED OUT TO BE A B737 ON ABOUT A 4 NM FINAL. HAD HIS XMISSION INCLUDED THE TA; I WOULDN'T HAVE NEEDED TO QUERY HIM ABOUT THE APPARENT CONFLICT; AND COULD HAVE COMPLIED WITH HIS CLRNC 'ON TO HOLD.'