/usr/share/ltsp/init-ltsp.d/06-ltsp-init-common is in ltsp-client-core 5.3.7-0ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | # This file is sourced
. /usr/share/ltsp/ltsp-init-common
|