I did a search, but didn’t find it. The thing with searches is, that unless you use the same terminology as the programme, it may not work.
O.K., after that preamble, how can I have a barline on the left of the staff? Setup options doesn’t seem to make provision for this, though I’m sure it’s in there somewhere.
Presumably you mean that you want a systemic barline at the left of the system when there is only one staff in the system? If so, Dorico can’t do this at the moment, but it’s on our list of things to add in future.
Sure, when we implement this we will do so as an Engraving Option, so it would naturally apply to all layouts with systems consisting of only a single staff anyway.