A nit.
https://codereview.appspot.com/579280043/diff/579290043/Documentation/notation/input.itely File Documentation/notation/input.itely (right): https://codereview.appspot.com/579280043/diff/579290043/Documentation/notation/input.itely#newcode464 Documentation/notation/input.itely:464: escaped with backslashes. This is confusing. 'Alphabetic characters' and 'non-ASCII characters' are not different sets but are overlapping. What about The name of a variable should not contain (ASCII) numbers, underscores, dashes, or space characters. All other characters Unicode provides are allowed, for example Latin, Greek, or Chinese. In other words, variable names like @code{HornIII} or @code{αβγXII} work. Any combination of characters is allowed if the variable name is enclosed in double quotation marks. In this case backslashes and double quotation marks need to be escaped with backslashes (not that you actually should use them). Examples: @code{"foo bar"}, @code{"a-b-c"}, @code{"Horn 3"}. https://codereview.appspot.com/579280043/
