Discussion
indirect page mechanism - prompt page - Help info obsolete
prompt page concept is deprecated in 7.3 and the "mode" option in pages&classes tab is removed from the activity rule form.I understand if earlier versions used prompt pages, Pega supports that implementation as of today.
Looks like the help content (under heading: "Sharing pages between original and branch activities") is not updated in the below 7.3 help URL. Kindly update this to avoid confusion.
https://pdn.pega.com/sites/pdn.pega.com/files/help_v73/procomhelpmain.htm#methods/branch/branch.htm