@Bea 17:41 Dec 30, 2014
Yes, and it should be there, of course: omission of the opening question mark in Castilian is definitely incorrect. People do quite often omit it nowadays, even on this forum, either because they can't be bothered to include it or because it's not available (or not easily available) on their keyboard. It's fairly unusual to see an opening question mark in SMS or Whatsapp messages. Perhaps we are seeing the beginning of its gradual disappearance.
It doesn't have a very long history. The RAE first prescribed opening question marks in its 1754 Ortografía, but it was a long time before anyone took any notice. I don't remember ever seeing one in an eighteenth-century printed book, though there probably are some. A century later, in 1853, Domínguez said this in his Diccionario Nacional: "Al principio de la pregunta se usa el signo (¿) y al final (?): pero si esta es muy corta, se suele suprimir la primera de estas notas". This is more or less the situation today in Catalan and Galician, where opening question marks are only used in long questions. Not until 1884 did the RAE itself include the (¿) sign in its dictionary definition of "interrogación". | 
