I recently asked a question about how to use the contents of a register in an ex command in nvi here and a discussion ensued about whether nvi is on topic. Prior to asking the question, I assumed that it was on topic because a) vi is in the name of the site and b) a tag for nvi already existed (admittedly with few questions).
I was curious so I tried hunting around for related discussion that might shed some light on the on-topicness of nvi. This question and its answers would suggest yes because nvi is a vi-like text editor. Also, there are many shared features that vim and nvi both have because of their vi heritage.
A comment on a different question, proposes a different test though: whether the community collectively has sufficient expertise in the software to answer questions about it. This would make a strong argument against defining questions about nvi to be on-topic. The documentation on it is very sparse because the editor is not popular. User-oriented documentation or information about customization is also sparse. This post was the most useful discussion I could find anywhere before asking my question. The nvi source code is also hard to read, which I guess is another barrier to answering questions about it.
