Twice last week, sets of friends visited my home for the first time. In both cases, they fooled me completely. They knocked on the front door. I was waiting at the back door, where friends are expected.

“I didn’t know you had a front door,” another friend remarked when I told her about this curious behavior.

I do, but it’s for cosmetic purposes only. In friendship, you know you’ve made it when you reach back-door status. If you knock on the front door, you’re selling something.

In all other dealings of life, the object is to move up front. Practicing back-door politics means you’re sneaking your people or policies in where honest folk can’t see them. In basketball, when a guy slips behind his defender to break for the basket, he just ran a back-door play. He sneaked out. In business, deliveries are taken in the grimy alley out back while valued customers are admitted through the front door to all the fancy trimmings.

But in friendship, it’s a sign of respect to be admitted through the back door into a kitchen or breezeway. They may not be tidy, but it’s home.

My front door, as it turns out, opens into the living room. Visitors immediately either walk into the end table by the couch or trip over the ottoman. My furniture is arranged for use of the living room, not for use of the front door.

The back door swings right into the kitchen, where there’s room and where it’s more likely that cookies can be found.

Maybe this is a country living kind of thing. Maybe city folk use their front doors for more than an ornamental piece on which to hang a wreath, ribbon or bells in the winter.

Almost always, driveways lead to the back of the house. Picnic tables and lawn chairs are out back. Decks generally are better in the back. Friends are out back.

So if you visit a friend in the country, generally, you go to the back door. Sometimes, you don’t even knock. You walk right in and sing out. If nobody’s home, help yourself to a cup of coffee and a sandwich, leave a note on the table and come back later. If there’s a burglar, chase him out.

Then there’s the side door. In many homes, that substitutes as the back door. I’m not sure what it means at my place. I have a side door to nowhere. It’s on the second floor and opens to nothing but a scenic view. No steps. No deck. Not even a rope ladder or knotted sheets. Just a straight drop to the ground.

I have no idea why the builder did this. Maybe there was some rule back then that a house had to have three doors. And he, being cantankerous like me, said, “Fine. Here’s your door. Now if you’ll just step right this way…”

It does work as an emergency exit in case of fire, but I’d suggest taking a running leap. You’re going to break your leg in the fall anyway. You might as well land as far away from the burning building as you can before you have to start rolling.

So go ahead, drop by my place. If I don’t know you, knock on the front door. If you’re a friend, meet me around back. But if I ask you to meet me at the side door… well, perhaps you ought to go knock on someone else’s door.