Most of my calls are Mobile to Mobile but is see that most are coded N&W. As budone said, this means Night & Weekend minutes; not counted against your monthly allowance. Also what is "planallow"? These are calls during peak times that DO count towards your monthly plan allowance. I do get some calls that say M2Mallow and that makes sense. What do these mean?
N&W is night and weekend minutes, M2M is mobile to mobile, Plan Allow is your actual "peak" minutes or what you are allowed in a month, if you ever see anything that says "Span" that means that the call started before 9pm and then nights and weekend minutes took over. Hope this helps!