Universal Pepper Nomenclature
One code for one pepper, no matter what people call it.
Pepper names are a mess. There are nineteen ways to spell pequin. Half a dozen unrelated peppers get sold as Purple Tiger. Some growers say Bhut Jolokia and some say Ghost. A Universal Pepper Number doesn't replace any of those names. It sits behind them and describes the pepper itself: the species, the color it ripens to, its skin, the shape of the pod, and how hot it runs. The last three digits tell apart peppers that match on all of that.
Look up a code
Capitals don't matter, and 44 is the same serial as 044. 4,055 peppers have a code so far.
How to read a code
- Six parts, always in this order, always split by hyphens.
- Two ripe colors? Both letters go in, in alphabetical order. RW is red and white.
- Pattern and skin codes are two letters each, run together in alphabetical order. STWR is striped and wrinkled. A plain, smooth pepper with nothing else going on gets SM.
- One pod form per pepper: the shape it usually sells as.
- Heat goes by the top of the SHU range, or by the one number on file when that is all there is. A pepper rated 2,500 to 8,000 SHU is a 4, not a 3. A single figure of 8,000 is a 4 as well.
- No SHU on file is written as # in the heat place. When a number is added, that place becomes the digit and the board can reissue the code.
- A cross between two species shows both letters, like A×C. Typing AxC works too.
- A code needs a species, a ripe color and a pod form. If one of those is missing, anybody with an account can add it.
The code tables
Heat (T)
| Code | SHU | For example |
|---|---|---|
| 0 | 0 to 500 | Bell, Banana |
| 1 | 501 to 1,000 | Cubanelle, Aji Dulce |
| 2 | 1,001 to 2,500 | Anaheim, Padrón |
| 3 | 2,501 to 5,000 | Guajillo, Piment d'Espelette |
| 4 | 5,001 to 15,000 | Jalapeño, Hungarian Wax |
| 5 | 15,001 to 50,000 | Cayenne, Tabasco |
| 6 | 50,001 to 100,000 | Chiltepin, Rocoto |
| 7 | 100,001 to 350,000 | Habanero, Scotch Bonnet |
| 8 | 350,001 to 1,000,000 | 7 Pot Douglah, Fatalii |
| 9 | over 1,000,000 | Ghost Pepper, Carolina Reaper, Pepper X |
| # | No SHU recorded | Filled in when a number is added |
Species (S)
| Code | Species |
|---|---|
| A | C. annuum |
| B | C. baccatum |
| C | C. chinense |
| F | C. frutescens |
| P | C. pubescens |
Wild and lesser-grown species
Varieties use their species' code. C. annuum var. glabriusculum is A.
Ripe color (C)
| Code | Color | Notes |
|---|---|---|
| R | Red | Standard red, including deep reds |
| C | Crimson / Burgundy | Darker red hue, bordering burgundy |
| O | Orange | Bright or standard orange |
| T | Peach / Salmon / Pastel | Lighter warm tones |
| Y | Yellow | Lemon, bright or canary yellow |
| G | Green / Mustard | Fully ripe but stays green or mustard |
| B | Brown / Chocolate | Deep brown |
| A | Caramel | Reddish-brown or warm brown |
| D | Gold | Metallic yellow or golden |
| P | Blue / Purple | Anthocyanin blue or purple |
| Z | Pink | Pale red or unstable pink |
| W | White / Cream | Includes ivory and pale yellow |
| K | Black | Fully black when ripe (rare) |
| M | Multicolor / Irregular | Each pod may ripen to a different color |
Held for future colors: E, J, Q, X. U is retired. A code that still uses it means Blue/Purple, and new codes use P.
Pattern and skin (P)
| Code | Trait | What it looks like | Seen on |
|---|---|---|---|
| BB | Black Blush | Black flush over the base color | Black Pearl |
| BC | Bleeding Calyx | Calyx pigment bleeds onto the pod | BBG7 Bleeding Borg |
| BD | Banded | Horizontal rings or bands of color (rare) | Unstable hybrids |
| BL | Blotched | Large irregular splotches | NuMex Twilight, Bolivian Rainbow |
| BT | Bicolor Tips | Tip is a different color than the base | Some Chocolate Ghosts |
| CC | Colored Calyx | Calyx is red, purple or black | Purple UFO |
| CI | Color Inversion | Ripe pod is darker than unripe | BBG7 hybrids |
| CK | Corked | Rough, scar-like cracking on the skin | Jalapeño |
| FL | Flecked / Speckled | Small dots or spots of another color | NuMex Twilight, Calico |
| GH | Ghosted / Shadowed | Faint halo near the stem or tip | Early ripening ajis |
| MB | Marbled / Swirled | Colors blended and swirled | Purple UFO, Aji Omnicolor |
| MO | Mosaic / Mottled | Patchy, virus-like color breaks | Calico |
| MR | Multicolor Ripening | Passes through 3 to 5 colors while ripening | NuMex Twilight, Aji Omnicolor |
| MT | Matte / Powdery | Dull, waxy finish | Wild and C. pubescens types |
| NV | Netting / Veining | Network of thin lines on the skin | Overlaps with corking |
| PA | Persistent Anthocyanin | Purple or black stays through full ripeness | Pimenta da Neyde |
| SM | Smooth and Glossy | Smooth, slick skin. The default when nothing else is recorded | Aji Fantasy, Padrón |
| SP | Splashed | Brush-stroke smears | Chimeras |
| SR | Segmented / Ribbed Coloring | Color splits along the pod segments | Rocoto crosses |
| ST | Striped | Vertical stripes of alternating color | Fish, Trifetti |
| TA | Tail | Scorpion tail at the tip | Butch 'T' Scorpion |
| TR | Translucent Skin | You can see the inside of the pod | Pimenta da Neyde |
| VA | Variegated | Cream or white sections on the pod | Fish |
| WR | Wrinkled | Deeply creased, crumpled skin | Red Savina |
| WT | Warty / Bumpy | Raised, blistered texture | Carolina Reaper, Bhut Jolokia |
Pod form (F)
| Code | Form | Notes |
|---|---|---|
| B | Bell | Blocky bell |
| C | Curled / twisted | Curled or twisted pods |
| D | Heart | Heart-shaped |
| F | Apple / blunt bell | Apple-shaped or thick and blunt, including most rocotos |
| H | Habanero-type | Lantern-shaped habanero pods |
| J | Standard tapered | Jalapeño and Anaheim types |
| L | Long / tapered | Long and thin, like cayenne |
| M | Mushroom / bonnet / UFO | Flattened, wider than long: Scotch Bonnet, UFO |
| N | Noodly | Long and noodly |
| P | Pequin / small bullet | Small bullet pods |
| S | Short / squat | Short and squat |
| T | Round / tomato / cherry / marbles | Round: tomato, cherry, marble |
| U | Unusual / unclassified | Fits nothing above |
| W | Wedge | Wedge-shaped |
Held for future forms: E, Q, R, X.
Who issues codes
The WikiPepper Foundation issues every UPN, and its board is the site's administrators. Every code comes out of one ledger, so two peppers can never hold the same code. A serial is never handed out twice, even after its code is retired.
What the board looks for
A pepper that's been grown for eight years or more, is past F8, and comes true from seed. That's a guideline, not a hard rule. The board may still issue a provisional code for a newer line when the record shows what sets it apart.
When the data changes
If someone corrects a pepper's traits, its code doesn't change by itself. The board looks at it and can reissue the code. The old code keeps working and points to the new one.
UPN Spec 1.0 (2026)
Dispute a code
Think a coded pepper isn't really distinct, isn't stable, or has the wrong traits on file? Tell the board why. Codes themselves are issued only by the WikiPepper Foundation.
A dispute needs a free WikiPepper account. It goes to the board at info@wikipepper.org.