I'm creating an OS X app and during it's setup (the very first launch) I need user to select a few entries from a list (a one-columned table). Usually on OS X user is able to select a single line from the table and multiple lines when holding Command key.
I'd like to make multiple selection available without any additional effort of getting to command key. Yet I'm hesitant to do so because of possible users' habit for multiple selection from other applications.
What would be the way to denote possibility of multiple selection without command key? Should I add a piece of text saying so or maybe I just should leave the current interaction behavior as it is on most (all?) OS X apps?
The Apple HIG says nothing about item selection in list views (table/outline views).