prerm is in libreoffice-lightproof-ru-ru 0.3.2+1.5+git20140515-2.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | #!/bin/sh
set -e
if [ "$1" = "remove" ]; then
# remove .pycs
find /usr/lib/libreoffice/share/extensions/lightproof_ru_RU/pythonpath -name "*.pyc" -exec rm {} \;
fi
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