ipython %bookmark error: quotes don't fix this
Using "double-quotes" fixed it for me.
Have a go with:   %bookmark md "C:/Users/user1/my documents"
This is probably a stupid question, but I can't find an answer. 
%bookmark dl 'C:/Users/user1/Downloads' works, but %bookmark md 'C:/Users/user1/my documents' doesn't work, throwing error:
"UsageError: %bookmark: too many arguments"
How to fix this?