According to https://developer.apple.com/documentation/os/logging?language=objc, the following value types have built-in formatters in os_log:
time_t, timeval, timespec, errno, iec-bytes, bitrate, iec-bitrate and uuid_t.
But according to https://developer.apple.com/videos/play/wwdc2016/721 (28:42)
there is also support for sockaddr, in_addr and in6_addr via %{network:sockaddr}.*P, %{network:in_addr}d and %{network:in6_addr}.16P.
Are these officially supported so I can start using them, and if so, are there any other such 'undocumented' types that are also officially supported.