Hello Derwent76
You are referring to your previous question about the Swiss Travel Pass: https://community.sbb.ch/d/22110-swiss-travel-pass-validity
The Saver Day Pass (SDP) can be bought by anyone, not matter if you are a resident or a tourist. It is available as e-ticket only.
The full fare Saver Day Pass does not need any further card; the half fare Saver Day Pass requires the (Swiss) Half Fare Card in addition. The (Swiss) Half Fare Card does not have to be active in order to purchase the SDP, it has to be presented with the SDP upon ticket check only.
The Saver Day Pass grants unlimited travel on the Swiss public network to all inhabited places and on panorama trains (PE), but not for mountain excursions (cable cars, cogwheel trains, etc). It does not grant any discounts for mountain excursions either (if it is used together with the Half Fare Card, it is the Half Fare Card that grants the discount, not the Saver Day Pass itself). The only mountain excursions where the SDP is valid: Mt. Uetliberg, Mt. Rigi., Mt. Stanserhorn, Klewenalp, Stoos, Mt. Rochers-de-Naye.
Please note: all Saver Day Passes are only valid together with your physically available passport or official ID card. You must present it during the ticket check.
Kind regards,
Roland