Questions on Delivery Context Ontology

Greetings,
I'm trying to understand the underlying assumptions about the structure of the Delivery Context Ontology as a framing for work that I need to do, re: describing capabilities of head-less devices for transformation of web-based content. I'm trying to work through the document, though am a newbie wrt OWL...  From what I can see, there has been a good deal of progress from the initial version, though there are still a few things that I do not understand, and may be based on the notion that this is for mobile devices...


1)       Characteristics about the notion of a Display seem to be scattered throughout the ontology, e.g., usablePixelsX and usablePixelsY have Delivery Context class as a domain while characterColumns and characterRows have Device class as a domain. Is there a reason why these properties do not have Display class (and only Display class) as their domain?

2)       Bluetooth stuff is similarly spread across the ontology. My recollection of Bluetooth (from 10 yrs ago) is that it is a type of Personal Area Network (as is ZigBee, etc.). If there a reason why Bluetooth is considered part of the Hardware Aspect rather than part of the Network Aspect of the device?

3)       Here's a nitpick...  Why does Device have a Width property, but not a Height property? Also, is this the width (and height) of the overall device or the width (and height) of the display on the device. If the latter, how do you handle devices with 2 displays, like my cell phone?

I am going through the Ontology very slowly and will likely have more questions along these lines. Are these useful to you, i.e., do you want me to send a more comprehensive list of questions?

Cheers,
Deborra Zukowski