Teleportation Circle

As you cast the spell, you draw a 10-foot-diameter circle on the ground inscribed with sigils that link your location to a permanent teleportation circle of your choice whose sigil sequence you know and that is on the same plane of existence as you. Any creature and any solid or liquid object that enters the circle instantly appears within 5 feet of the destination circle or in the nearest unoccupied space if that space is occupied.
Many major temples, guilds, and other important places have permanent teleportation circles inscribed somewhere within their confines. Each such circle includes a unique sigil sequence—a string of magical runes arranged in a particular pattern. When you first gain the ability to cast this spell, you learn the sigil sequences for two destinations on the Material Plane, determined by the DM. You can learn additional sigil sequences during your adventures. You can commit a new sigil sequence to memory after studying it for 1 minute.
You can create a permanent teleportation circle by casting this spell in the same location every day for one year, or by casting a permanency spell upon it. You need not use the circle to teleport when you cast the spell in this way.

Rune Sequences

The runic sequences which address the teleportation circle and declare its destination, have magically significant morphologies which direct the cirlce's teleportation magic. The runes do not correspond to any natural language, but have substantial overlap with the set of characters used in other magical writing systems. There are 16 runes in common use on Cordeca. When expressed to players, the runes are transcoded as hexadecimal values 0-F.
Because other planes have different magical foundations, they require different runic morphologies. It is very possible for a spellcaster to learn the runic alphabets of other planes, and to construct cross-planar teleportation circles, but this requires additional research beyond what is confered by learning this spell.
Teleportation circles are normally constructed with two sets of 10 runes each. The "bottom" set defines the source address of the current circle. The bottom set is normally not changed for the lifetime of the circle and it is conventionally chosen by the caster by extending a personal prefix which they have unofficially claimed. For example, a caster might assert that he uses addresses with the prefix "0 1 2 3 4 5 6 7 8". He might then create circles with bottom addresses like "0123456781" or "01234567A", hoping that other casters will not encrotch upon his prefix.
Learning a caster's prefix or learning a bottom address used by them, makes it reasonable to guess other addresses which the caster might also use. Casters are therfore encouraged to keep their addresses in confidence.
If two circles are active contemporaneously with the same bottom sequence, foreign teleportation circles will prefer to send contents to the geographically-nearer circle. It is possible to create an intercepting decoy circle between the true destination, and a direction which should be excluded from connections.
The "top" set defines the destination address to-which the circle will teleport (ie. the bottom-address of the target). In temporary teleportation circle, the top address may be changed with each casting using the same material cost. In permanent circles, the top address is fixed.
Cordeca Rune Sequences
Python Command to Generate Sequences

python3 -c 'from random import randbytes; print(" ".join(randbytes(5).hex().upper()))'