DEC PDP-8 Paper Tapes?

I picked up a bunch of unknown paper tapes last week. I was sorting through them today and found several tapes that have "Digital Equipment Corporation Programmed Data Processor" printer along the length of them. The label on one of them also says "Memory CKR BRD (LOW)", "Memory CKR BRD (HIGH)", "Memory ADDR BRD (LOW)", "Memory ADDR BRD (HIGH)". That one also has "PDP-8" written on it in pencil. So I'm guessing that these are all for the PDP-8. The tapes are marked variously "DB3", "DB4 SIMAT #1 3 SW TEST", "PAL III", "Combined BB#51, INT #15, CORR #21 and Patches 1-11". Does anyone know what these titles mean? All of the tapes are on blue plastic spools that are 4 inches in diameter and 1 1/4 inch thick. Each spool has a removable blue plastic cylinder (with one end closed) that slips over it. In the center of the spools are white plastic inserts with a hole and three radial drive slots. The covers are marked "Reel-Dex Part No. 30" and "Numeridex Incorporated Wheeling, Illinois 60090". It's pretty obvious that the spools are made to be used directly in a PT reader. But does anyone know what kind? Joe