Sweet. Thanks. I was only indenting by one space.
curl -s http://www.gnu.org/software/coreutils/manual/coreutils.html
| sed '/<li>.*-inv.*p>:.*[^>]<.a>/!d;s/.*#//;s/-inv.*:/:/;s/<.a>//'
|sort
"A long, long time ago when I was <em>mastering</em> Linux..." [emphasis mine]