Hello Folks,
Citrix has released a new Version for the Linux Receiver documentation explaining a couple of settings, the new document is already for the Receiver Version 13 but most settings are similar to Receiver 12 and explaining a lot of useful settings that can be found in the IGEL Setup->System->Registry->ICA->wfclient area.
You can found the documentation here: Download Linux Receiver Guide
Cheers
Michael