Quote handling: quotes aren't necessarily balanced in a well-formed text but parser expects them to be

[VioletGiraffe]

• Adjacent dual double quotes can collapse into one: "What do you mean, "What do I mean?"
• Single quote can be used inside double quotes: "What do you mean, 'What do I mean?'"
• Point can be on the either side of the closing quote: http://english.stackexchange.com/questions/127618/how-to-correctly-use-double-quotation-marks-at-the-end-of-a-sentence

[VioletGiraffe]

In Unicode text different symbols may be used for opening and closing quotes, which makes keeping track of them easier. See #33.