Why do I get "_doc" when running "bundle exec bin/todo help -c"

I’m on page 31 of the book. When I run bundle exec bin/todo help -c I get

_doc
done
help
list
new

_doc is not listed on the book. Why am I getting it?

The version of GLI in the book has a feature (not discussed in the book) that generates RDoc of your app’s UI. In GLI2, this was changed to <a href="mailto:_doc”>_doc@. There’s not currently a way to avoid having that show up. If you think that’s important, file an issue on github and I’ll look into it (it’s probably very simple, just didn’t think of it)

It’s cool, just wanted to know WHY it was showing up, I wasn’t sure if I was doing something wrong or if it was supposed to show up. That makes sense, thanks!