Sumptuary laws:
The sumptuary laws (from Latin sumptuāriae lēgēs) are laws that attempted to regulate consumption; Black’s Law Dictionary defines them as “Laws made for the purpose of restraining luxury or extravagance, particularly against inordinate expenditures in the matter of apparel, food, furniture, etc.”[1] Historically, they were laws that were intended to regulate and reinforce social hierarchies and morals through restrictions, often depending upon a person’s social rank, on their permitted clothing, food, and luxury expenditures. [Wikipedia]
Noted in “On Whose Head?” Janet L. Factor, Freethought In Action (currently offline):
Another is that modesty codes serve the same function as the old secular sumptuary laws: they make certain it remains clear to all who belongs to a superior class and who belongs to an inferior one. Don’t own land? No silk for you! Suffer that scratchy homespun like a proper peasant. Attire becomes a label designating rank.