Guildmasters, purchased spaces and a manager's headquarters — the crawlers are building an institution.
The Guild System advances entirely offstage while Carl is at the studio. Mordecai reports that the group talked Imani into being the guildmaster and that they have already purchased a space for the guild. The next step is an upgrade called a manager's headquarters, which Katia wants to borrow money to buy — because, as Mordecai explains it, that would let him keep his room when Katia disengages. Sort of.
The mechanics implied are concrete: a guild needs a named guildmaster and a bought space, upgrades can be purchased on top of it, and a member disengaging from the guild otherwise costs the rooms attached to them.
The framework the crawlers are using to formalise their group, with the ownership rules that make Mordecai's room contingent on it.
Also appears in books you've already read — spoiler-safe to their endings: