NQOD is a brand name of Square D, it is not listed as a tradmark. It is a lighting and appliance branch circuit panel rated at 240VAC max.
All of Square D's lighting panels (as opposed to loadcenters)are prefixed with an N. In the old days their power panels started with an M.
The QO stands for the type of breaker and really means nothing. QO was simply a new letter designation (older breakers were types MO and XO). However 15 and 20A 1Pole QO breakers feature a "QWICK-OPEN" construction.
The D stands for dual connection bus bars. The panel accepts plug-on and/or bolt-on breakers. The older NQO panel was for plug-on only and the NQOB was bolt-on only.
