Known issues with Rack and ECMA-262

Known issues with Rack and Web servers

Known conflicts regarding parameter parsing

* Many users have differing opinions about parameter parsing. The current
  parameter parsers in Rack are based on a combination of the HTTP and CGI
  specs, and are intended to round-trip encoding and decoding. There are some
  choices that may be viewed as deficiencies, specifically:
   - Rack does not create implicit arrays for multiple instances of a parameter
   - Rack returns nil when a value is not given
   - Rack does not support multi-type keys in parameters
  These issues or choices, will not be fixed before 2.0, if at all. They are
  very major breaking changes. Users are free to write alternative parameter
  parsers, and their own Request and Response wrappers. Moreover, users are
  encouraged to do so.