Quoting Michael Paoli (michael.paoli@berkeley.edu):
Many will, by default, issue NOTIFY from all authoritative nameservers. At first that might seem odd, but, I believe the logic goes about like this: the overhead is low clients that don't care can/will (mostly) ignore authoritative (whether primary or secondary) has no way of knowing how other authoritatives downstream of it are configured, so, e.g. some authoritatives may only get their data via other secondary(/ies), and not direct from master, etc.
Yes, as I was saying, I had a faint recollection that the matter of Aaron T. Porter's ns.primate.net issuing NOTIFY for domains on which it's secondary, not primary, had come up in some of my earlier efforts to puzzle out strange nameserver behaviour. I just couldn't remember exactly how that had unfolded -- other than my obviously having decided to take no action.
Obviously it's at worst harmless, and I can/should just add another "ignore" line to the logcheck configuration so I stop being told about it. I just was taking a moment to try to figure out whether this is deliberate behaviour and why it's there. Your answer will serve splendidly. Although, I'm bothered that the usual information sources don't seem to cover this.
On the third hand, I didn't look _too_ closely, e.g,, maybe it's covered in the Zytrax's "DNS for Rocket Scientists" or the related dead-tree book _Pro DNS and BIND_.
Slightly weird, anyway.