RAE redirects the definition of quizás to quizá but I wonder if there's any implicit, secret rule that I am not aware of as to whether quizás is preferred over quizá.
I've seen both forms used almost indistinctively even on the same text.
What's your take on this? Would you use both words in the same text? Do you have a rule to chose one or the other depending on the word succeeding it, for example?