Published: 14 January 2025 by Dan Williams
Last Updated: 27 July 2026
Stamp collecting has its own shorthand. On this website, and in Apollo’s Lots eBay listings, I sometimes use common philatelic abbreviations to describe condition, catalogue references, postmarks, perforations and general quality.
This practical stamp grading and philatelic abbreviations glossary explains the main terms used in Apollo’s Lots listings, including UM/MNH, MM/MH, VFU, FU, GU, SF, SG, Spec and Cat, along with listing terms such as perf, perfin, SON, CDS, wmk and misperf.
These terms are intended as a guide to the descriptions, but the full listing text, condition notes and images should always be considered together.
Stamp grades and catalogue abbreviations
| Abbreviation | Meaning | How we use it |
|---|---|---|
| UM / MNH | Unmounted Mint / Mint Never Hinged | An unused stamp with original gum and no hinge mark. Other faults, if present, should still be noted separately. |
| MM / MH | Mounted Mint / Mint Hinged | A mint or unused stamp with original gum, showing a hinge mark, mount mark, hinge remainder or other evidence of previous mounting. Can be lightly or heavily mounted. |
| MLH / MVLH | Mint Lightly Hinged / Mint Very Lightly Hinged | More specific mounted mint terms. They describe the degree of hinge or mounting evidence on the gum. |
| MNG | Mint No Gum | An unused stamp without any remaining gum. |
| OG | Original Gum | Used where the gum is original to the stamp. Gum condition may still vary, so faults such as hinge marks, disturbance, toning or missing gum should be considered separately. |
| VFU | Very Fine Used | A used stamp with strong eye appeal and no obvious faults, usually with a light, neat or well-placed cancellation. |
| FU | Fine Used | A sound used stamp with a good or moderate postmark. Generally very collectable, but not as choice as VFU. |
| GU | Good Used | A reasonable used example, perhaps with a heavier postmark, off-centre appearance or small imperfections such as a tiny crease or pulled perforation. Often acceptable to many collectors. |
| AU | Average Used / Fair Used | A lower-grade used stamp with more obvious imperfections, such as rough postmarks, several pulled or ragged perforations, thins or creasing. |
| SF | Space Filler / Gap Filler | A stamp with clear faults, often bought as a cheaper representative example until a better one is found. This may include noticeable thins, tears, cuts, repairs or other condition problems. |
| SUPERB / XF | Superb / Extremely Fine | Can apply to used or mint stamps where the usual grades do not quite do enough justice. It may refer to centring, freshness, cancellation, margins or general eye appeal. |
| SG | Stanley Gibbons | A Stanley Gibbons catalogue number used to identify the stamp. This usually consists of numbers and/or letters, and is used to locate the corresponding stamp in the relevant Stanley Gibbons catalogue. |
| Spec | Specialised catalogue reference | A more detailed specialised catalogue reference, usually used for shades, varieties, flaws, papers, watermarks, phosphor differences or other specialist details. |
| Cat | Catalogue value | A guide value from the relevant catalogue. It is not the same as the retail price or expected sale price. |
Most stamps listed by Apollo’s Lots include the SG number, denomination, colour and corresponding grade or quality where relevant. If additional information is needed, the listing description may include condition notes, catalogue details or other observations, with high-resolution images forming part of the overall description.
Other common stamp listing terms
Not every stamp abbreviation related to the grade. Some terms describe perforations, watermarks, postmarks, errors, format or other features that may affect identification, condition, collectability or value.
| Term | Meaning | How we use it |
|---|---|---|
| Perf | Perforation / Perforations | Used either as a perforation measurement, such as perf 14 or perf 15, or in condition notes such as short perf, pulled perf, rounded perf or nibbled perf. Perforation measurements refer to the number of perforation holes or teeth in a standard 2 cm space. |
| Short perf / Pulled perf | Perforation fault | Terms used where one or more perforation teeth are short, missing, pulled or damaged. These faults can affect grade and value, especially on otherwise fine stamps. |
| Imperf | Imperforate | A stamp without perforations. Some imperforate stamps were issued that way, while others may be errors, proofs, cut-down examples or stamps from imperforate sheets. Context is important, so imperf should not automatically be treated as an error. |
| Perfin | Perforated initials or insignia | A stamp with small holes punched through it to form initials, a name, pattern or logo. Perfins were often used by businesses and organisations to discourage misuse of postage. Once often treated simply as damaged stamps, they are now collected as a specialist area, with some highly sought after. |
| Misperf | Misperforated / Misperforation | A stamp where the perforations are not correctly aligned with the printed design. Misperfs can be subtle or dramatic. Clear examples are collected as stamp errors, although value depends on visibility, severity, condition and demand. |
| Wmk | Watermark | Short for watermark. Watermarks are part of the paper and can be important for identifying issues, printings and varieties. |
| Inv wmk / Rev wmk | Inverted watermark / Reversed watermark | Used where the watermark is upside down, reversed, or both inverted and reversed. Watermark varieties can be important on some Great Britain issues. |
| Phos | Phosphor | Short for phosphor. Phosphor bands or phosphor coatings were used to help automated mail sorting. Some listings may refer to phosphor bands, phosphor omitted varieties or phosphor differences. |
| CDS | Circular datestamp / Counter date stamp | A round dated postal cancellation, usually showing the place and date. A clear CDS can add interest to a used stamp, especially where the strike is neat, readable or relevant to the issue. |
| SON | Socked on the nose | A clear, central and readable cancellation, usually struck neatly across the face of the stamp. Often used for circular date stamp cancellations where the place and date are well positioned and easy to read. |
| CTO | Cancelled to order | A stamp cancelled without normal postal use, often for collectors or packet material. CTO stamps are common in some areas of world collecting and may be valued differently from genuinely postally used examples. |
| FDC | First day cover | A cover, envelope or card cancelled on the first day of issue of the stamp or set. The cachet, postmark, address and condition can all affect collectability. |
| MS / M/S | Miniature sheet | A small sheet containing one or more stamps, often with decorative margins or additional printed design. Miniature sheets may be collected mint, used or on cover. |
How grading works in Apollo’s Lots listings
Stamp grading is partly descriptive and partly subjective. A grade gives a quick indication of condition, but it cannot describe every feature of a stamp on its own.
Where relevant, Apollo’s Lots listings may also mention centring, perforations, gum condition, cancellations, thins, creases, tears, repairs, toning, short perfs or other visible faults. For scarce stamps and varieties, lower-grade examples can still be collectable, especially where the variety itself is difficult to find.
Catalogue values are included for reference where useful, but they should not be read as a direct selling price. Actual market value depends on condition, scarcity, demand, eye appeal and availability.
For more on the catalogues, references and practical tools behind Apollo’s Lots listings, see Stamp Catalogues, References & Tools I Use.
Frequently asked questions
Happy collecting – Dan.