Close Open Tabs on Login


we have a Partlet Application and the customer wants to have closed all open Tabs on login but one. I know how i can achive that for a single one user. But for 500 users it’s a bad solution.

How can i set the preference for the entire application?
Is it possible to define that in a shell/shellrules?

In the CAF Application Runtime Configuration > Portlet Application > User Attributes i’ve the possibility to choose
“Close Open Tabs on Login”. But whats the parameter name?

Thanks in advance