SPL files are the actual spool (print job) files.
TMP files are usually associated with LPR print jobs.
SHD files provide information about which printer the print job was sent to and from whom the print job came. An SHD file is a "shadow" file that keeps track of what logical printer a (same number) xxxxx.spl file goes to. It also contains the file's order in the queue, the user who sent the file to the printer, and other information. These files are usually deleted unless the logical printer settings state otherwise.
Article ID: 264662 - Last Review: Oct 31, 2006 - Revision: 1