danman,  In accordance with the international Guitar Players Compendium, there is one particular bylaw that is documented within the compendium's infamously renowned and beneficent charter, that clearly states and most emphatically stipulates by Divine Proxy, that you can use what ever gauge that feels, plays and sounds to your likings, EXCEPT for any gauge or type of flat-wound strings, (IT'S THE LAW).  Do they even make flat-wounds any more. NOTE: This information has been procured from the personal library of Ima Pulin Yerleg