I'm use a regular expression match to extract just the part within the brackets so what I have left is JSON. If I make a POST in XML, nothing is returned.
This sounds like an issue with Chicago's (?) 311 API itself and not the documentation (this project is the documentation). You should probably send an e-mail to developers@cityofchicago.org .
All responses I receive are returned preceded with a two digit alphanumeric string and proceeded with "0".
36 [{"code":400,"description":"Valid location required"}] 0
I'm use a regular expression match to extract just the part within the brackets so what I have left is JSON. If I make a POST in XML, nothing is returned.