New tests and test improvements are now included in the newly published version of ANSI/ASHRAE Standard 135.1-2013, Method of Test for Conformance to BACnet.
According to ASHRAE, the standard defines a standard method for verifying that an implementation of the BACnet protocol provides each capability claimed in its Protocol Implementation Conformance Statement (PICS) in conformance with Standard 135, BACnet® -- A Data Communication Protocol for Building Automation and Control Networks.