RJSVM/node_modules/ripple-lib/dist/npm/common/schemas/objects/currency.json

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "currency",
  "description": "The three-character code or hexadecimal string used to denote currencies",
  "type": "string",
  "link": "currency",
  "pattern": "^([a-zA-Z0-9<>(){}[\\]|?!@#$%^&*]{3}|[A-F0-9]{40}|drops)$"
}