/usr/share/acheck/rules/common.rules is in acheck-rules 0.3.3.
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 | rule # double
type fix
regex \b(\w+)\s+\1\b # word start, word, space, same word, word end
hint Double
fix $1 # remove matched word to fix
|