friends... today i recieved my app I had sent to CIC returned back to me along with fees

they put a letter asking me to correct some date fields and send the application back to them...
also on the application for PR form in the upper right corner in the office file no. field they had
written a 10 character no. starting with :
K90xxxxxxx
and stamped as PNP.
I wondering if this no. is same as AOR or application file no. any clues ?
ainpdude,
Nice to know that they requested for correction while assigning some number. I am not sure what this number means but I could get the meaning to some of terms from CIC help section.
Identification TypeYou may have one or more identification type(s), depending on your application(s). Refer to your correspondence or official documents to determine which identification type(s) you have received from Citizenship and Immigration.
Client ID NumberYou will find this number on official documents issued to you from a Citizenship and Immigration Canada office, Case Processing Centre or visa office where you submitted your application. Your "Client ID Number" has four numbers, a dash (-), and four more numbers. (Example: 0000-0000).
Receipt Number (IMM 5401)You will find this number on the document that was filled out and stamped when you paid your fees at a financial institution or on the official receipt you obtained when you paid your fees on the Internet. Your "Receipt Number (IMM 5401)" starts with a letter, followed by nine numbers. (Example: B000000000).
Immigration File NumberYou will find this number on any official document issued to you from the visa office where you submitted your application. Your "Immigration File Number" starts with the letter "B", and is followed by nine numbers. (Example: B000000000).
Permanent Resident Card numberYour "Permanent Resident Card" number is located in the top left corner on the back of your card. The "Permanent Resident Card" number will begin with two letters followed by 10 numbers. (Example: RA0302123456).
Confirmation of Permanent Residence number (IMM 5292 or 5509)You will find this number in top right corner of your Confirmation of Permanent Residence document issued to you by a Citizenship and Immigration Canada office or by the visa office where you submitted your application. Your Confirmation of Permanent Residence number starts with a "T" followed by nine numbers. (Example: T100000000).
I think most likely it is Immigration File Number; but hey I might be wrong.
Did you check if your check for fees was encashed?
Keep us posted.
My application reached CIC Buffalo on 5th Jan; since I haven't heard from them, is it safe to assume that my paperwork was complete?

Thanks,
Taps