Man, I feel like an amateur but I don't know the answer to what seems like an easy question. When users run reports on the server(AS400) where on the 400 does it store these reports?
If you mean the output from the reports, it stores those in the PRINTQUEUE directory in IFS. It should be in your System folder. Like for 8.9, it would be in the B9SYS folder.
Before erp9, they are members of the printqueue file in the traditional FS in the System library.
The PDF files are the F123456 files, the number is the OW job number. They are in ASCII (since PDF is only valid that way, so you can't view them on the iSeries, but you can ftp them in bin mode to wherever.