The document in 8.5 Beta 1 Designer Help entitled “Domino URL Commands” does not contain any information on XPages, or a “see also.”
Similarly, the document “URL commands for opening pages” does not contain any information or a “see also” for xpages.
Subject: to view an xpage on a server
the url syntax would be:
http://server/mydb.nsf/xpagename.xsp
Or you can even just set your db web launch property to start on a given xpage!
Subject: Worked great, but existing documentation very misleading
That worked great, and it wasn’t obvious. 
Of course, I followed the previous design pattern of just trying
database.nsf/xpage1
What is misleading in the documentation are the documents
Lesson 1: Opening an XPage
which gives the example
http://domino.company.com/servlet/xsp/xphwt.nsf/page1.xsp
and
Lesson 11: Vuiewing an XPages element
which also discusses paths relative to server/servlet/xsp.
Subject: Notified documentation team <>