B777-200 CREW WAS CLRED INTO POS BEHIND THE DEPARTING A319. THE CTLR DID NOT MAKE CLR THERE WAS A SECOND A319 THAT THE CREW DID NOT SEE AT EGLL.

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WE TAXIED FROM GATE AROUND E SIDE OF ARPT ONTO CLOSED RWY USED FOR TAXI PURPOSES AND TOLD TO STOP AT RWY 27R HOLDING POS. WE COMPLIED; STOPPING ON CLOSED RWY/TXWY WITH 1 ACFT (AN AIRBUS) AHEAD. THE AIRBUS WAS WAITING ON A TXWY THAT CONNECTED THE CLOSED RWY/TXWY AND RWY 27R; AHEAD AND TO THE L; PERPENDICULAR TO OUR POS. APPROX 5 OTHER ACFT WERE ALSO WAITING FOR RWY 27R ON ANOTHER TXWY THAT ALSO FED INTO RWY 27R FURTHER W (L) OF OUR POS; HDG E. THERE WAS A 10 MIN DELAY IN TKOF CLRNCS DUE TO AN ERRANT ACFT IN THE DEP CORRIDOR. WHEN TKOFS RESTARTED; TWR TOLD US TO TAXI INTO POS ON RWY 27R AFTER THE AIRBUS TAKES OFF. AFTER THE AIRBUS TOOK OFF; WE TAXIED INTO POS ON RWY 27R. AS WE CROSSED THE RWY BOUNDARY; A CONVERSATION WAS HEARD BTWN TWR AND ANOTHER ACFT TO THE EFFECT THAT 'ACR X SEEMS TO BE GOING AHEAD SO WE'LL WAIT HERE.' AFTER LINING UP ON RWY 27R; ACR Y COULD SEE AN A319 HOLDING SHORT OF THE RWY. WE RADIOED TWR THAT 'IF WE FOLLOWED THE WRONG AIRBUS; DO YOU WANT US TO TAXI CLR?' TWR ADVISED 'NO' AND CLRED US FOR TKOF. THERE WAS NO VIOLATION FILED TO OUR KNOWLEDGE. THERE WAS NO DANGER OF ANY ACFT TAXIING INTO ANOTHER ACFT. HUMAN FACTORS WERE INVOLVED IN THAT UNITED KINGDOM CTLRS APPEAR TO REFER TO ACR Z ACFT AS 'ACR Z' AND ACR Y ACFT AS 'ACR Y' WHICH IS NOT A NORMAL PROCESS FOR UNITED STATES CREWS.