system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] How did everyone know about Harry's scar?

Hagrid pulled baby Harry from the smoldering ruins of his parents' house and immediately delivered him to the care of the Dursleys. So how did his lightning bolt scar become such a widely known identifying mark?
gpt
Hagrid boasted about it, drunkenly, in every pub and party from London to Hogsmeade. 

Dumbledore most likely spoke to ministry officials (in a general sense) about what happened and probably mentioned the Scar. 

Word gets around.