The Rarest Urbit Sigils

What makes an Urbit sigil rare?

Urbit Names

First let's take a brief look at Urbit names.  All ships in the Urbit network are named using 3-letter syllables, and there are 512 syllables in total.

These unique syllables are separated into two groups: 256 prefixes, and 256 suffixes.  The syllables are listed in full at the bottom of this article.

The names of the 256 galaxies in the urbit network are the same as the 256 suffixes:

Star names are made from just one word, a prefix followed by a suffix:

Planet names are made up of two 6-letter words:

In this example pin and dir are prefixes, and wyl and bet are suffixes.

Point Numbers

Each of the 256 prefixes and 256 suffixes also have an 8-bit numerical value, ranging from 0-255.

For example, both doz and zod have the value 0, but one is a prefix and one is a suffix.

Hexadecimal numbers (beginning with 0x) are useful for reading point numbers, as you can view the data byte-by-byte.

dev is a suffix with value 179 or 0xb3, and the point number of galaxy ~dev is also 179.

 0x 00 00 00 b3 

The point number for a star is a 16-bit number where the suffix value is in the lower 8 bits, and the prefix value is in the upper 8 bits.

ron has the value 0x60 and dev has the value 0xb3, so the point number for ~rondev is 0x60b3 or 24,755 in decimal.

 0x 00 00 60 b3 

Planets are represented by 32-bit numbers, but the syllables in the name do not match up with the bytes in the point number.

 0x a0 57 60 b3 

Planet names are obfuscated, so it's not obvious which star they come from. This system effectively shuffles all the planet names and distributes them amongst all the stars.

If they were not obfuscated, each star would have a very predicatable and boring list of planets:

Instead, these are the actual names:

Basic Glyphs

The syllables in an Urbit name translate exactly to the glyphs in the sigil for that name.  Every syllable has its own glyph.

The individual glyphs are combined left-to-right and top-to-bottom.

When you use the Sigil search tool, you can see all the glyphs are categorized into 12 general shapes.

Even though all 512 glyphs have one of these 12 shapes, they are each unique due to other stylistic elements.

Rarity

The key to what makes a sigil's shape rare is the number of glyphs in each group, and whether those glyphs are prefixes or suffixes.

From this we can see that some sigils are impossible because certain glyphs never appear in the prefix or suffix position. The rarest sigil shapes are those using the least common glyphs for a particular position.

Here are the uncommon prefixes from that table:

These are the uncommon suffixes:

ryl is the only suffix of that shape, and sigils with 2 ryl appear only once per star on average.

You will notice that the rarest shaped sigils contain the syllables above.

The Rarest Sigils

Let's check out some of the rarest and most aesthetic shapes. These rare sigils won't be found for sale on urbit.me, but you can browse all the planets and see what stars they belong to.

See the full list of rare shapes here: Rare Sigil Shapes

These are only samples of the rare shapes, browse through the rest here: Rare Sigil Shapes

Appendix

All Prefixes

All Suffixes