PSN Single-Letter Username Glitch: What Actually Broke

PSN briefly allowed users to claim single-letter Online IDs like A, B, X, and Z, even though Sony’s public username rules require 3–16 characters. It looks less like a planned feature and more like a validation failure somewhere in PSN’s identity stack, showing why client-side checks are never enough and why all platforms need consistent server-side validation across APIs, account services, and databases.