I recently translated the 'new' rules for the Spanish language, published in 2010 by the RAE.
The RAE are Real Academia Española, and they are the body who define everything about the Spanish language.
The rules take a few minutes to wade through, and could be summarised on one page, but I prefer to stick to the unexpurgated version.
They cover things we already know, like ch and ll no longer being in the alphabet, they clarify the name for all the letters, they explain why foreign words are given Spanish spelling, they explain the rules for using prefixes, and they also state that a tilde should not be used to differentiate the likes of solo the adverb (formerly sólo) and solo the adjective, or to differentiate demonstrative pronouns from adjectives.
It's five pages if you're bold enough to download and peruse it.
RAE 2010 Rules.pdf 102.56KB 300 downloads