While reviewing changes today I noticed that within the pipe sizing section (5.1.10.11.1.3) the terminology there changed to reference "terminal(s)" instead of "individual station outlets and inlets".  This prompted me to check what the definition of terminal was within chapter 3 which is:

3.3.186 Terminal - The end of a flexible hose or tubing used in a manufactured assembly where the user is intended to make connection and disconnection.

This definition seems like it is specifically referring to outlets / inlets that are installed within a manufactured assembly.  NFPA 99 also contains a definition for Station Inlets & Station Outlets:

3.3.181 Station Inlet - An inlet point in a piped medical/surgical vacuum distribution system at which the user makes connections and disconnections.

3.3.182 Station Outlet - An outlet point in a piped medical gas distribution system at which the user makes connections and disconnections.

Based on the way all of these terms are used within Chapter 5, I believe they are all referencing the same thing.  It would make more sense to have the definition for Terminal match the wording for Station Inlet & Station Outlet.  Better yet, do away with the terms Station Inlet & Station Outlet and just make the definition of Terminal be:

Terminal - The point in a piped medical gas, medical surgical, or WAGD distribution system at which the user makes connections and disconnections