origins (i.e "of long hill) basically operate like last names for dreams (eggshell dino people) since they don't have like... hereditary names due to not reproducing (new ones just pop out of the ground). their name codes work like:
City/Tower/Region-District/Subregion-Birth year-Cycle-Birth order in year. so for instance, echo's name code is O'O3-18-8-22, which is short for Oldest Tower, O District Third Level, 18th year of the 8th cycle, 22nd-born. and then "echo" is more like a nickname.
now, if echo was doing stuff in a totally different city, they'd be echo of oldest. if they're doing stuff in other parts of oldest (which is a MASSIVE complex) they're echo of district o. and if they're within O, they're echo of third level. Etc.
the more populous an area is, the more vague nicknames get. third is called third because their hometown, long hill, has very few new dreams born there due to its derelict nature. the name marks them immediately as either from somewhere extremely small/backwater or somewhere really important, and it's easy to tell which one!