Quick histroy lesson.

On the other site their was a sub called cedibledefence. It was supposed to be a serious place, where people in the know discussed the finer points of blowing shit up.

It soon became filled with pompous posters and mods who usually had zero military experience spouting very serious sounding bullshit.

r/NCD was created as a shitpost parody of r/CD.

In one of those strange internet flips NCD became a place that was visited by military and people in the MIC who mostly shitposted but often the comments section was filled with some quality analysis of the shitpoted topic.

EG: Some of the best analysis in the early weeks of the Russian invasion was to be found buried in a comment thread on r/NCD where the post was a picture of a fighter plane rendered as an anthropomorphic furrie.

TLDR:

r/cedibledefence: a place for those with little knowledge to sound very serious about things they know little.

r/NCD: A place for people who do know shit to shitpost like they don't.

And when the fediverse came along, the name stuck.