/usr/share/cups/ppd-updaters/splix.ppd-updater is in printer-driver-splix 2.0.0+svn315-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | DRIVER_REGEXP='^drv:///splix-[a-zA-Z0-9]*\.drv/'
GENNICKNAME_REGEXP='s/,(\s*SpliX|)(\s*V\.?|)\s*[\d\.]*$//i'
|