Blocking Empty UA Outside of Feed Requests
I wanted to add an htaccess rule to NLJ blocking requests from empty user agents (and "-" user agengs). I looked into the best way to do it and found a 2017 answer on Stack Overflow. This solution is interesting because it explicitly allows requests to the site's feed. While I have not noticed empty user agent requests for our feeds, there are many niche feed readers out there, so I went with a modified version of this snippet to be on the safe side.
https://social.emucafe.org/naferrell/blocking-empty-ua-outside-feed-02-04-26/