Original text:
Sending a Message with Message Properties inconsistent with the Selection Properties of the Connection yields an error.  The following Message Properties are supported: 7.5.1.

Reviewer comments:
I inserted the text that I quoted in this issue, with a minor tweak.
List discussion: Kyle: NAME
I agree with the conclusion of NAME above - in which case we should leave things as they are. Other views?
I agree that if the application does nothing then communication should be reliable. But I understand Kyle's comment as asking about the relationship to the selection property Reliable Data Transfer (Connection). If you for example set that to Avoid and the TAPS system selects SCTP as the protocol, then if you do not set Reliable Data Transfer (Message) on a message I assume it will be sent as an unreliable message. So in that sense the reliability of a message defaults to whatever is set for the connection, unless it is overridden by setting Reliable Data Transfer (Message). And the default for Reliable Data Transfer (Connection) is Require so what NAME writes still holds but it is a different thing.
So if we agree upon Reliable Data Transfer (Connection), then it would seem less confusing for Reliable Data Transfer (Message) - to use the same logic. Does an apps writer need to know the data will be sent as an unreliable message? (I'm not sure I like "avoid reliable data transfer" as a meaningful concatenation of keywords BTW:-).
Let's see what needs to be done. Suggestion: the only textual change would be to add the following, at the beginning of Section 7.5, just before "The following Message Properties are supported": "Connection Properties describe the default behavior for all Messages on a Connection. If a Message Property contradicts a Connection Property, it overrides the Connection Property for the specific Message. For example, if "Reliable Data Transfer (Connection)" is set to "Avoid" and a protocol with configurable per-Message reliability is used, setting "Reliable Data Transfer (Message)" to "Prefer" for a particular Message will ensure that this Message is reliably delivered. If the underlying protocol can not support this per-Message behavior, this Message Property choice will yield an error."
Thanks! No more comments now :)

Revised text:
Sending a Message with Message Properties inconsistent with the Selection Properties of the Connection yields an error. <ins> Connection Properties describe the default behavior for all Messages on a Connection.  If a Message Property contradicts a Connection Property, and if this per-Message behavior can be supported, it overrides the Connection Property for the specific Message.  For example, if "Reliable Data Transfer (Connection)" is set to "Require" and a protocol with configurable per-Message reliability is used, setting "Reliable Data Transfer (Message)" to "false" for a particular Message will allow this Message to be unreliably delivered.  Note that changing the Reliable Data Transfer property on Messages is only possible for Connections that were established with the Selection Property "Configure Per-Message Reliability" enabled. </ins> The following Message Properties are supported: 7.5.1.