forgot how Compressor makes a "16x9" ntsc dvd

Dumb question, I haven't done this in a while. What Compressor setting should I use or modify to compress anamorphic video content so that the resulting sd dvd plays it at 16x9 letterbox?

I'm working with a anamorphic Qt master out of an Avid. I used the Compressor preset for DVD 90min best quality which does say 16x9 but the resulting dvd is a squeezed 4x3.

It is Compressor that creates the flag*, yes? It's not Toast is it?

Pls help, deadline looms. Thanks in advance.

Best,

Paul


* sets the WS bit