If you call you'll only get the official byline. It varies as they check you in, BUT....they seemed to allow 2 carry on's as long as only one was a suitcase styled one (check the dimensions as they were measuring them to be sure they were small enough) and the 2nd one was a small backpack or purse or handbag. They were letting you have 15 pounds in each bag. If any bag looks heavy or too large they will target it. We had so many people have issues at the front of the line that they got more lenient towards the back of the line. Others have said that the first of the line is more lenient and they are worse towards the end.
So take your back pack and make sure it does not weigh more than 15# and your carry on does not weigh more than 15#. Technically they were giving you 30# of carry on luggage without add'l charge.
Again a travel vest SOLVES MANY ISSUES. I got mine from scottevest but there are other good ones.