Roy Smith wrote:

I fly out of HPN, a busy Class D with everything from scheduled airlines to
two flight schools doing primary training. CD generally tells spam cans to
"advise tower and ground you're IFR".

Should the tower already know I'm IFR without my having to remind them? Of
course they should. But it doesn't cost me anything to play along with
their request, so why make a big deal out of it?

Complying with an instruction to "notify tower..." is one thing. Being expected
to do so in the absence of an instruction is another. OTOH, there's that pesky
AIM reference I hadn't been aware of until this thread.

Dave