Abbreviations
Whether you're just getting started or brushing up on collecting cachets, the following are commonly used cachet abbreviations. We use some of these for describing our covers.
| CF | Crossed Flags |
| SA | Stamp Addressed |
| TA | Typed Addressed |
| PA | Pencil Addressed |
| IA | Ink Addressed |
| LA | Label Addressed |
| FDOI | Label Addressed |
| LMCSS | Letter Mail Code Sort System |
| NCR | National Cash Register Company |
| PM | Postmaster |
| USIR | United States Internal Revenue |
| PPMF | Parcel Post Mailing Facility |
| TAP | Tagged After Perforating |
| OCR | Optical Code Reader |
| FDC | First Day Cover |
| APS | American Philatelic Society |
| AFDCS | American First Day Cover Society |