B737-300 had an unclr clearance and controller disinterest in the clearance question on taxi in sfo.

Attributes
ACN	502742
Time
Date	200102
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : private
ASRS Report	502742
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	502737
Events
Anomaly	non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous
Air Traffic Incident	Pilot Deviation

Narrative:

On taxi from maintenance to gate, cleared via zulu sierra, hold short of runway 28R. I complied, but when cleared to continue, was told I should have continued around the extended centerline of runway 28R. The commercial airport plate xyz page and the taxi markings suggest the instruction 'zulu sierra' can be followed by crossing runway 28R or by going around runway 28R. I had pointed this out 30 mins earlier to ground, but they were not concerned. They were concerned later but unwilling to admit their instructions were not precise. Supplemental information from acn 502737: we were cleared by ZZZ ground control to taxi from the maintenance to gate via zulu, sierra, bravo 1, alpha, hold short of runway 28R. After taxiing clear of the maintenance west gate we understood we were on taxiway Z based on the taxiway signs. We held short of the north side of runway 28R on taxiway south and were instructed to cross. Once we were on the runway, the controller told us he wanted us to taxi around the end of runway 28R on taxiway Z and to call the tower once we were at the gate. The captain called the tower supervisor and was told we would have had a runway incursion if not for the actions of one of his controllers.

Original NASA ASRS Text

Title: B737-300 HAD AN UNCLR CLRNC AND CTLR DISINTEREST IN THE CLRNC QUESTION ON TAXI IN SFO.

Narrative: ON TAXI FROM MAINT TO GATE, CLRED VIA ZULU SIERRA, HOLD SHORT OF RWY 28R. I COMPLIED, BUT WHEN CLRED TO CONTINUE, WAS TOLD I SHOULD HAVE CONTINUED AROUND THE EXTENDED CTRLINE OF RWY 28R. THE COMMERCIAL ARPT PLATE XYZ PAGE AND THE TAXI MARKINGS SUGGEST THE INSTRUCTION 'ZULU SIERRA' CAN BE FOLLOWED BY XING RWY 28R OR BY GOING AROUND RWY 28R. I HAD POINTED THIS OUT 30 MINS EARLIER TO GND, BUT THEY WERE NOT CONCERNED. THEY WERE CONCERNED LATER BUT UNWILLING TO ADMIT THEIR INSTRUCTIONS WERE NOT PRECISE. SUPPLEMENTAL INFO FROM ACN 502737: WE WERE CLRED BY ZZZ GND CTL TO TAXI FROM THE MAINT TO GATE VIA ZULU, SIERRA, BRAVO 1, ALPHA, HOLD SHORT OF RWY 28R. AFTER TAXIING CLR OF THE MAINT W GATE WE UNDERSTOOD WE WERE ON TXWY Z BASED ON THE TXWY SIGNS. WE HELD SHORT OF THE N SIDE OF RWY 28R ON TXWY S AND WERE INSTRUCTED TO CROSS. ONCE WE WERE ON THE RWY, THE CTLR TOLD US HE WANTED US TO TAXI AROUND THE END OF RWY 28R ON TXWY Z AND TO CALL THE TWR ONCE WE WERE AT THE GATE. THE CAPT CALLED THE TWR SUPVR AND WAS TOLD WE WOULD HAVE HAD A RWY INCURSION IF NOT FOR THE ACTIONS OF ONE OF HIS CTLRS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.