title: JSON-API - use custom HTTP header or meta information for 'product-code'
body: <p>The company I work for has several products that consume shared APIs. Previously we've passed the 'product-code' as a custom HTTP header. It's generally only used for things like determining a product-specific API key, or included in certain log messages, etc. It's generally not persisted to a database.</p>
  <p>Recently we've started adopting the JSON-API spefification for building APIs.</p>
  <p>Would the recommendation be to use <a href="https://jsonapi.org/format/#auto-id--meta-information" rel="nofollow noreferrer">meta information</a> to specify the 'product-code', or to keep this as a custom HTTP header?</p>
  <p>Cheers.</p>