I one time by sort of accident coined a config format by parsing todo.txt It was so useful it stuck around for much longer than I had intended to. Rather than comment out stuff it just looks for "=" and ignores everything else.
conf = {};
configFile.split('\n').forEach( function(x){
y = x.split(' ');
if(y[1]=="=") conf[y[0]] = y[2];
});
Everything is a comment with exception of lines like:speed = 100 km/h
weight = 60 kg
maxBuffer = 200 chars (between 100 and 300 works best)
output: {"speed":100,"weight":60,"maxBuffer":200}
It had walls of text with headings and something configurable sprinkled in. Crockford would be screaming. lol
Reminds me of Whitespace [1] where anything but a whitespace is a comment.
[1] https://en.wikipedia.org/wiki/Whitespace_(programming_langua...