Search Query String

I would like to double-check the Search Query String. The Top New to Post  section only allows for keywords but no phrases, is that correct? How are the keywords separated? With spaces or no spaces: Acne,Pimple,Zits  OR  Acne, Pimple, Zits Do I need to put quotations marks around them? How does the search query function works? Does it find a match for at least one of the keywords requested for it to retrieve it, or does the article have to contain all the keywords listed?  Is there a max limit to the number of keywords that I can insert into the query? There's no boolean search option, is that correct? Such as using If, Or, And between keywords. ------------------------------------------------------------------------------------------------------------- Regarding phrases, this is only allowed in the Custom News to Post section, is that correct? Does the phrase need to be in quotation marks"?  for example, "Treatment for Acne" Thank you...