RIO DE JANEIRO — Timm Jamieson was worried at first.

After collecting Olympic pins for more than 30 years, he arrived in Rio to find little interest in one of the Games' most enduring — and endearing — traditions. Brazilians didn't seem to understand the custom and barely gave a second look at the die-hard collectors who spread their wares on the sidewalk each day.

“It has taken a while for the Brazilian public to catch on,” said Jamieson, who is attending his 14th Olympics. “In the beginning, they thought it was very odd, but they understand it now.”

The pins date to the first modern Olympics in 1896, when separate pins were created for judges, athletes and officials. The first pin produced as a souvenir for fans was a silver stick pin at the Stockholm Games in 1912, according to historians. And the Nazis took the tradition to an entirely different level in 1936 when they mass-produced millions of pins as part of propaganda for the Berlin Games.

In recent decades, the pins have become the Olympics' unofficial currency. They're used to elicit favors, establish advantageous relationships and show one's gratitude. People wear them on lanyards like scouting badges and talk about them proudly.

But they don't just trade pins. They buy and sell, too, with their Olympic spirit on display throughout the exchange. If someone wants to trade, the big collectors will usually try to find something to swap — even if the trader is offering a pin already in wide circulation.

“I'm a little tougher to trade with toward the end because I have most of what I want,” said Jamieson, who has swapped 2,500 pins here. “But I try to be fair. I'm not looking to take advantage of anyone.”

This year's hottest pins feature Rio's iconic Christ the Redeemer statue and the Olympic rings. The cleverest one that I've seen here, without question, was worn by farrier Kenny Bark, who trims and shoes horses for U.S. equestrian team. He fashioned a horseshoe nail into a pin and wears it on his credential.

The most sought-after pin, however, is a three-dimensional one created for NBC. It features a colorful toucan with wings that open wide.

With only a limited number in circulation, the toucan pin remains elusive for even the most dedicated pin traders.

“I've done well here, but I don't think I'm going to get one,” said Carol Lord, a Canadian trader who swapped more than 1,800 pins during the last two weeks. “There's always Korea [in 2018] and Tokyo in 2020.”