Perhaps we could use a custom C# documentation tag for this? Something like:
/// <response code="400">Bad request; parameter XYZ was invalid</response>
/// <response code="401">Authentication credentials required for this API</response>
/// <response code="403">Account not authorized to access this entity</response>
/// <response code="404">The Pet entity was not found</response>
Swagger.Net does not have a clear way to document the various HTTP status codes that may be returned by an API.
The Swagger spec for errors codes is @ https://github.com/wordnik/swagger-core/wiki/Errors
Perhaps we could use a custom C# documentation tag for this? Something like: