Appearance-coding systems are subcultural, not universal, urban knowledge.

Evidence

Systems for coding the meaning of appearance may not be known or even available to all city dwellers. Subgroups within the city may develop portraits of certain social types which are only known by, and meaningful to, them. Thus, for example, cabdrivers have developed an extensive typology of cab-users, the attributes imputed to each type having a certain predictive value, particularly as regards tipping. — Lyn H. Lofland, World of Strangers_ Order and Action in…, 564

Categorization

• XREF: Complicates Lofland’s own stranger-ordering framework: appearance is not an equally available code across all urbanites, undermining the claim that appearance is a primary-ordering category accessible to everyone.