Several areas of this specification are overly conversational—particularly topic sentences.

Line 161 is unfortunately conversational. Perhaps starting sentence similar to "OBIX addresses the need to normalize information from devices and present it in a standard way."

Section 3.2, line 201: suggest first sentence replaced with "OBIX provides simple syntax rules able to represent the underlying object model."

Section 3.3, line 231: "As the focus of OBIX is to make information available over the internet, it makes sense to use the Uniform Resource Identifier (URI) to identify OBIX objects. URIs, as defined in RFC3986, are the standard identifiers for resources on the internet.

245-246 URI references define a standard way to normalize the expression of relative URIs.

252-254 The World Wide Web is in essence a distributed collection of documents hyperlinked together using URIs. Similarly, OBIX presents controls and sensors as a collection of documents hyperlinked using URIs.
267: Remove "Probably" (redundant after "for example")

9.2 1174-1187 needs a re-write using language that isn't as impressed with itself for discovering the internet. Also see comments on URIs, above.

Line 1520: Suggest deleting "if that is important to the application"

Line 1876: recommended deleting "as possible"

2252-2254: "Now fictionalize the that"? Suggest: "The system next detects that the front door is closed, i.e., the alarm point transitions to the normal state. When the Client next polls the Watch, the Alarm would be included in the Feed.