W-2 Entry Uncommon sit. checkboxes - nonqualified pension plan not on W-2

When entering my W-2 information, the main form entry is followed by a list of "uncommon situations" which includes a line "Nonqualified pension plan not on my W-2."  The ? help icon then speaks only of "What if I have a section 457 plan on my W-2?"  First, those are two different questions...  Second, I don't understand whether I should or shouldn't check this?  I am still employed, and contribute to a nonqualified "deferred compensation plan", but it is not a tax-exempt NGO.

So... I DO have a nonqualified pension plan, and NO, it does not show up on my W-2.  Thus, I might think I should check that box...

However... why would it??? It never has before, and I did not receive income from it.  I contributed TO it, so my income in box 1 looks "low" relative to 3 and 5, but unless there is some reporting requirement for contributions I don't see why I would check that box?!?

What is the right answer?