I'm writing my first grammar. It's going pretty well but, I've captured all the stuff I care about and now I have some extra junk I don't care about. How can I express something like, "S = word data junk", where I'm interested in part of the pattern and then afterward there is maybe some "whatever"?

@mathpunk you might want the “hide” syntax (`<>`)?

https://github.com/engelberg/instaparse#hiding-content

you could capture all the other junk with <#'[\s\S]*'>

excellent, thank you!