COMMUTER FLC CONFUSED REF HOLDING CLRNC. FAIL TO DSND IN TIMELY MANNER.

Narrative

METERING WAS IN PROCESS AT MSP AND WE WERE GIVEN A CLRNC FOR HOLDING AT CANEN INTXN (20 DME S OF FGT). THE CLRNC READ: 'HOLD S OF CANEN INTXN AS PUBLISHED AT 7000 EXPECT FURTHER CLRNC XX45.' WE CONTINUED AT 10000 FT FOR ANOTHER 5 MI AND NOTICED AN ACFT AHEAD OF US ABOUT 5 MI AT THE SAME ALT. MY CAPT POINTED THE ACFT OUT AND I SUGGESTED THAT MAYBE WE SHOULD HAVE STARTED OUR DSCNT TO 7000. MY CAPT STATED THAT HE WASN'T AWARE OF THE 7000 ALT IN THE CLRNC BECAUSE HE DIDN'T HEAR IT AND THE ALT WAS NOT PUT ON THE ALT ALERTER. IN THE MEANTIME; I WAS TRYING TO GET A BREAK ON THE RADIO SO I COULD QUERY ATC ON THE HOLDING CLRNC WE RECEIVED AND IF WE WERE SUPPOSED TO HAVE LEFT OUR ALT OF 10000 FT WHEN WE RECEIVED THE HOLDING CLRNC. MY CAPT STARTED TO PUSH THE NOSE DOWN TO AVOID CLOSE CONFLICT WITH THE OTHER ACFT AT OUR ALT. AT THE SAME TIME; ATC TOLD US TO START OUR DSCNT IMMEDIATELY TO 7000 FT. ATC DID SOUND URGENT; AND WE KNEW THAT HE WAS CONCERNED ABOUT THE CONFLICTING TFC. THERE WAS NO EVASIVE ACTION TAKEN. IN FACT; WE MAINTAINED VFR SEPARATION; BUT I AM STILL NOT SURE IF WE VIOLATED A CLRNC OR NOT. MY CAPT FELT THAT IT WAS (THE HOLDING CLRNC) A PLT'S DISCRETION CLRNC DOWN TO 7000 FT SINCE ATC DID NOT TELL US TO START DOWN RIGHT AWAY. WAYS WE COULD HAVE AVOIDED THE SIT: 1) I SHOULD HAVE DISCUSSED THE CLRNC WITH MY CAPT; MADE SURE HE HEARD AND UNDERSTOOD CLRNC. ASKED QUESTIONS. 2) DON'T FORGET STAND AND PROC (ENTERING ALT IN ALERTER); THIS WAS MY JOB! 3) MADE SURE I UNDERSTOOD THE CLRNC COMPLETELY! THINGS THAT LED TO THE PROB: 1) LAST LEG OF A 13 HR DUTY DAY. I WAS TIRED. 2) I FEEL I MAY HAVE BEEN A LITTLE PASSIVE IN THE VFR WX. WE FLEW IN A LOT OF IMC WX ALL DAY; 4-5 APCHS (IFR). IT WAS A RELIEF TO FLY IN VFR WX IN THE LAST PART OF OUR LEG ARRIVING MSP. 3) NOT MAKING SURE MY CAPT UNDERSTOOD THE CLRNC.