Feel free to decline this if it is too trivial. I was reviewing doc strings for new functions in Clojure 1.8.0, and those for clojure.string/index-of and clojure.string/last-index-of seem like they could be worded in a way that is much less subject to confusion.
Current doc string for clojure.string/index-of:
Issue: the lack of punctuation in the phrase "optionally searching forward from from-index or nil if not found" makes it appear that the "or" connects the first and last part of that phrase.
Screened by: Alex Miller
Patch clj-1837-v1.patch dated Jan 1 2016 modifies the doc strings of index-of and last-index-of as suggested.
I retracted my last comment, I think it's fine as is.