Each lending customer has a number assigned to them, so we use the customer number and add the note number, i.e., 12345 78910. To distinguish a commmercial loan from a consumer (personal) loan we begin the number with a series of letters CL for commercial, PL for personal then add the loan officers three initials. PL LMN 12345 78910.
Denials are distinguished differently. The first letter designates what area the loan application was received from, M for Mortgage, P for Personal, C for Commercial. The next is the application number, then the first four letters of the applicant's last name, then a file number. It would look something like this - P 11892 MATT395.
I know this seems like a great deal of work, but it makes finding the file a snap. And when you have 2,800 HMDA entries and over 3,000 CRA entries, well, you get the picture.