/usr/share/hashcat/rules/hybrid/append_ld.rule is in hashcat-data 3.30-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 | $a
$b
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$i
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$o
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$r
$s
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$w
$x
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$z
$0
$1
$2
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$9
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