/usr/share/dvb/dvb-t/au-unknown is in dtv-scan-tables 0+git20140107.1850cf8-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | # Australia ABC
# T freq bw fec_hi fec_lo mod transmission-mode guard-interval hierarchy
T 226500000 7MHz 2/3 NONE QAM64 8k 1/8 NONE
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