After reveiwing the OpenBSD Goals and Polices, it appears to me that the intent is that OpenBSD should be a free/Open Source system. But unless I am missing something that is not actually made clear. The polices page lists software licenses that are acceptable, and a few that are not, but I could not find an statement dfining what was and was not acceptable aside from by example.
The goals page section on the kernel prefers BSD Licenses over the GPL, requires source, explictly bans NDA's, but provides no guidance on the remainder of the cosmos of source providing licenses. Would proprietary software with source be acceptable ? The requirement to respect copyright's and licenses might narrow the field somewhat, but it still leaves alot of possibilites, pretty much any license that allows redistributing source. I could not find any reference or guidance concerning what is acceptable outside the kernel itself. It is possible to read all of this and conclude that OpenBSD is a free OS and that non-free software is unacceptable - including prohibiting non-free URL's in ports. It is also possible to understand this as allowing the inclusion - even in the kernel of code that does not even meet the weak OSI definition of Open Source.