Free McDonald’s Big Mac Jr’s In Tuscaloosa! There’s Only One Catch

Here it is, Sunday Night, and I am driving up 69 South. All of a sudden, I get a CRAVING for a McDonald's Quarter Pounder W/ Cheese. So, I decide to pull into Mickey D's. However, before I pull into The Drive-Thru, I look up at their marquee and see THIS sign which immediately catches my attention. It reads: "MONDAY 13  5  7 PM  FREE  MAC JR  ONE PER  PERSNO"  

Now, you KNOW I'm a Big Fan of FREE Food, and I imagine between 5 and 7pm tomorrow night, it will be a MADHOUSE over there. Hwy 69 South is usually a MESS at that time anyway. But I feel with THIS promotion for FREE BIG MAC JR'S, traffic will be even MORE congested than normal over there. However, I'm willing to put up with all that aggravation just for a FREE BIG MAC JR.  There's only one catch that worries me, though. There's a LIMIT to the amount of FREE BIG MAC JR's that are given out. As the sign says: "FREE MAC JR  ONE PER PERSNO"

So could somebody please tell me.........WHAT THE HELL IS A PERSNO!!! :-)