My bad for not being clear, I was really talking about the comment saying 429 means “too many requests”. By all means comment to say that service X has a rate limit of N req/min but a comment saying 429 means too many requests is exactly one of those things that’s better expressed in an enum.

301; 302; 401; 429; 504; I shouldn’t need comments to tell me what they are, nor should it be expected that anyone touching the code knows them off the top of their head.