While recorded history stretches pretty far back, it doesn’t go back far enough to tell us the name of the person who invented the yard sale. Perhaps it was an early caveman named Og Yard. Maybe Og had decided to unload a bunch of spears and clubs he didn’t need any more by staging a cave sale – or maybe he called it a “spring cave-cleaning sale.” No, wait a minute! That’s preposterous. That had to be Og’s wife.

No man would ever get rid of perfectly good spears and clubs.

When you think about it, the yard sale is really just an improvement on dragging your garbage can to the curb. Under the yard sale plan, you no longer pay anyone to get rid of your garbage. Instead, someone pays you — and they haul it away.

Every weekend, the area is awash in yard sale fever. True, they’re undermined these days by Internet interlopers like eBay and Craig’s List, but old-fashioned yard sales still flourish. That’s because they’re a quick, easy and free way to unload junk. And, as the saying goes, “One man’s junk is another man’s Chinese flat-bottomed boat.”

Yard sale entrepreneurs brazenly tack up signs everywhere — telephone poles, trees, hydrants and shrubbery.

I once saw a sad-faced dachshund saddled with a handmade sandwich board announcing an upcoming yard sale. Another time, a guy in our neighborhood pinned two separate placards on the top and bottom of a traffic sign at the end of our street. It then read “Be sure and STOP at our garage sale!”

In these summer months, they’re everywhere: YARD SALE! GARAGE SALE! And, the snootiest of them all — ESTATE SALE!

They’re all pretty much the same thing, but estate sale sounds the best because it suggests unbelievable treasures and magnificent antiques. Of course, the treasures and antiques are usually beat-up record albums, rusty exercise equipment, funky-smelling toasters — and old shoes (which are also often beat-up, rusty and funky-smelling). In other words, the stuff at the estate sales is pretty much the same stuff you’d find at the garage and yard sales. The difference is marketing.

Extravagant claims and alluring adjectives are key ingredients to any and all signage. For example, BIG, HUGE FAMILY GARAGE SALE!!!! is almost impossible to pass up. Plus, it’s always interesting to see just exactly how big and huge the family is.

Sometimes, an entire bunch of families will band together for a neighborhood or cul-de-sac sale. Of course, it’s not always possible to get total participation. There’s always one crabby neighbor who doesn’t want to take part. In that case, look for the signs that read: NICE NEIGHBORS’ YARD SALE.

If you’re staging a yard sale, remember that besides trying to unload your unwanted stuff, you are also putting your life on display.

Examples: If you are a married couple selling a bunch of old baby clothes, you are indicating that one of you has just had a vasectomy. When you put your Abdominizer or Thigh Master up for sale, you are pretty much telling the world that you have chosen to go to seed.

And if you’re a single man selling a collection of high heels and ballroom gowns – well, that’s your business.

My wife and I have held — and attended — a BIG, HUGE number of garage sales over the years, and learned a thing or two. So just in case you’re going to be staging or stopping by such a sale next weekend, here are some basic truths and rules.

• Advice for sellers:

1) The items you’re absolutely sure will sell, will not.

2) The stuff you want to get rid of the most will not sell.

3) The junk that is so lame that you’re embarrassed to even put it on display will sell. Immediately.

4) No matter what price you put on an item, someone will want it for less. If you put a 50-cent price tag on a dollar bill, someone will want it for a quarter. That’s just the way it is.

5) If you are a couple, make sure you have both agreed on what exactly is for sale. In my neighborhood once, a woman came home to find that her husband had just sold their beautiful, antique brass bed. Lucky for her, the buyers hadn’t yet departed with the bed, and the sale was quickly voided.

6) The worst place to hold a garage sale is in your garage. That’s because shoppers will constantly try to buy the things in there that aren’t for sale, like your workbench or freezer. (A tip: Put “SOLD” signs on everything that isn’t for sale. Like your antique brass bed, for example).

7) Once the sale is over, remember to take down your roadside signs, unless you want people to continue to show up for months.

• Advice for buyers:

1) Once the dumb guy sells you the bed, clear out as fast as you can.

Pat Cashman is a writer, actor and public speaker. He can be reached at pat@patcashman.com.