In English, we have different schools of thought on whether or not to use "double punctuation" at the end of a sentence. (See Terminal Points for a good chart that will help you abide by at least one school of thought in English.)
Knowing that punctuation conventions differ from one language to another, what is standard punctuation in Spanish as it relates to sentences that end with abbreviated words ending in a period? For example, should I write
¿De dónde es Ud.?
¿De dónde es Ud?
Along these same lines, what is the standard for parenthetical punctuation? Examples below are from the English Language & Usage StackExchange:
Honor your creativity and write down anything that comes to mind (no matter how silly!).
Honor your creativity and write down anything that comes to mind (no matter how silly!)
I tripped over this morning. I was distracted by a plane (or was it Superman?)
(or was it Superman?).
(or was it Superman)?
If you happen to know of a good resource (online or print, free or for purchase) that addresses punctuation conventions in Spanish, please include it in your answer.