Aspects of the subject matter described herein are directed towards indicating to a wireless network device which time-division duplex slot patterns (slot formats) are supported by a user equipment device, e.g., which slot patterns have went through interoperability and deployment testing (IODT) successfully with respect to the type of user equipment device. With the supported slot pattern information, the network can make an intelligent decision on scheduling downlink/uplink ratios, while selecting a slot pattern that the user equipment device is known to support. In one aspect, the technology adds a “Slot format IODTed” information element in the user equipment device capability information, which the network obtains when the user equipment device reports its capabilities to the network. In another aspect, the network can query the user equipment device for the supported slot format information.