[9fans] /n convention history?

[fgergo]

When I first met plan9 (2nd ed) I realized that /n was a very powerful
ordering concept. (Since then I usually create a /n or ~/n on every
unix where I will use mount to customize my ns.)
I'd like to know
- what's the story of /n? (why was it invented?)
- what does n stand for? (a set of n things?)
thanks,
fgergo