Sigils are the avatars of Urbit. They work as profile images that reference your Urbit name (your @p identity). For example, the planet ~datsyr-radser has the following sigil:
If you notice, this avatar is composed of 4 quadrants. Each quadrant corresponds to a syllable of the name.
The name datsyr-radser can be broken down into 4 parts:
dat | syr | rad | ser
Notice that we always break Urbit names into 3-letter syllables. Each of these syllables has an associated symbol:
If a planet has four symbols, this means that a star has only two, since the name of a star is composed of only two syllables (example: ~palnet).
Similarly, the sigil of a galaxy is just one symbol (example: ~net).
Why do sigils exist?
As the concept of identity in Urbit is important, the company Tlon had the initiative to create avatars that were exclusively associated with the names of the entities. This idea helps bring characteristics and personalization to each scarce identity within the network.
Sigils can be printed on t-shirts, logos, social profiles. It is another way to reference entities in the Urbit ecosystem, with a visual identity.
How are sigils formed?
The formation of sigils is made from separate symbol building blocks.
These symbols are combined to form more elaborate symbols. A programming script combines these building blocks based on the phonemes of Urbit names. This ensures that each Urbit name will have a unique and exclusive avatar.
Rarity of Sigils
Some sigils are rarer than others. If we analyze the base blocks that form the sigils:
We will see that it is possible to form some interesting structures for planets. For example, if all four quadrants of a sigil are based on a square shape, the result will be a completely square sigil:
About 1 million planets have this completely squared shape. This represents 0.024% of Urbit’s planets.
A suitable combination of semicircles can form completely circular sigils:
About 3 million planets have this completely circular shape. This represents 0.073% of Urbit’s planets.
Other examples of rare and interesting combinations:
The rarest basic form of a planet Sigil is this one:
Since there are only 16, I can show them all in one image. Their names and respective stars are indicated in the picture.
Note: You can see the full list of all prefixes and suffixes of Urbit names and their associated sigils in this page.