Swap Field Order: when should I use this?

So basically any Region-1 NTSC DVD (such as Star Trek The Next Generation Seasons 1 - 4 thus far) is probably produced using high-quality equipment that wouldn't mix up the field order? That's my last question. :)

Yep. You might find exceptions if you looked hard enough but generally I wouldn't worry about using field swap on DVD material. But that's just my own experience. Please someone else chime in here if there is a class of DVD's known to be a problem with this. - Tom

There was something mentioned in the article, I think in the PAL section

Yes, usually the only time you need to worry about it is PAL films, NTSC will be corrected by a good IVTC module anyway.