I found NT1 in a Microchip demo board schematic (103-00419-R1.pdf) but can't figure out what it means.
There is a box with a note saying "Default connection between 1-2. User to cut the trace if 5V VDD is needed.", with NT1 as a little box with wires going to pins 1 and 2 on the header.
I can't find the refdes on Wikipedia or Google in general, so I'm out of ideas. Here's a screenshot of the part in question (on the right side):