1) " so it's not a chore to tell what thread you're even replying to? ": I am lost by your statement.
Abe, all of your replies that I've seen in the past few days have been brand new threads (or possibly replies to yourself).
None of your replies have been properly threaded by my email client. This is in contrast to almost all of the other messages that I see on the NANOG mailing list, which do thread properly.
I start each of my reply by quoting a phrase or sentence of the message that I am responding to. To be sure the original message in included, I copy the last message following what I am writing. I also prefix it with the forum message tag such as in this case "NANOG Digest, Vol 170, Issue 20 Message: 33 ".
I'm now speculating that you are subscribed to the "digest" version of the mailing list instead of receiving individual messages.
Glancing at the headers, it appears as if NANOG is hosted on a Mailman mailing list. As such, I believe that you could change your subscription to use MIME formatted digest, which should include more proper RFC-822 copies of the messages. I believe that you could then reply to these individual messages directly and match the threading that I mentioned above.
The problem with digests is that they are brand new messages / threads. So replies to message text therein replies to a message that most of us don't receive (the digest message).
This should be enough for anyone to follow in the latest exchange, as well as tracing it back in history from the NANOG Digest, if interested. Anything more could I do to ease your efforts without beginning to create a long tail to a thread?
Prior to the message that I'm replying to, I was not aware that you were replying to the digest.
Those of us that receive individual messages as opposed to the digest don't have any visibility into the digest volume number, issue number, nor message number. For all intents and purposes it might as well be the "the 4th message that passed my spam filter after my last payday".
As for the copy of the message that you're including, I wasn't aware you were even doing that because you appear to be top posting and I wasn't seeing anything below your signature.
I'd encourage you to look at the MIME formatted digest where you can reply to copies of the original messages and maintain threading. Also, please consider not top posting.