Force all hyperlinks to display in parent frame

Hello! Is there a way to force the target for all hyperlinks in a frameless output (RH2020) to display in a parent frame (or new window, etc.)?

All of the hyperlinks and cross-references in my projects are currently set to be displayed in frame, page default. I need to update them to be displayed in the parent frame. Is there a way I can force this so that I don't have to update the target for every link in every topic in every language?

I've tried adding <base target="_parent"/> to the head of my master page, but that didn't work. It also didn't work to add it directly to the head of a topic. I also tried adding the following to my css, which also didn't work:

a {
 target: _parent;
}

Any other suggestions?