In 1983, the Cincinnati Reds devoted a page in their yearbook to a new uniform detail. Shortstop Dave Concepcion was having the letter C added to his left jersey sleeve. The letter didn't stand for "Cincinnati" or for "Concepcion." Rather, it indicated that Concepcion was the team's captain.

1983 Reds yearbook page announcing/explaining Dave Concepcion's captaincy "C." Larger version here: https://t.co/koG6AdSDk0 pic.twitter.com/9sRpgRFbXf — Paul Lukas (@UniWatch) May 22, 2017

This appears to have been the first instance of a relatively rare phenomenon: the C-clad MLB captain. Although no official records are kept on this type of thing, some recent Uni Watch research turned up only 13 examples of MLB captains wearing the C.

Perhaps that's not so surprising. Most MLB teams don't even have a captain, and those that do have one tend not to add a C to the player's jersey. And really, why should they? A baseball captain has no specific duties or responsibilities (unlike the situation in hockey, where only the captain or alternate captains can speak with the referee), and baseball's uniform heritage has generally tended to be more conservative. Imagine if Derek Jeter had worn a C for all those years he served as the Yankees' captain -- the mental image just doesn't compute.

Still, there are those 13 players, beginning with Concepcion in 1983, who've worn the C. And just as we recently discovered when going over the list of C-clad NBA captains, the MLB list is clustered among just a few franchises. Of the 13 MLB C-men, six came from one team, and four more came from two additional teams, suggesting that certain clubs have had more of a captaincy culture than others.

So who were these 13 kings of the C? Here they are, broken down by team:

Chicago Cubs (six players)

6 Cubs wore captain's C in 2000, '01 (clockwise from top left): Sammy Sosa, Mark Grace, Kevin Tapani, Rick Aguilera, Eric Young, Joe Girardi pic.twitter.com/BZyQG2LFCL — Paul Lukas (@UniWatch) May 22, 2017

In 2000, Cubs manager Don Baylor decided that the team needed a captain. Check that, the team needed several captains. So Baylor chose an outfielder (Sammy Sosa), an infielder (Mark Grace), a starter (Kevin Tapani), and a reliever (Rick Aguilera) and had a C put on each one's sleeve. Many fans probably missed the symbolism, since "Chicago" and "Cubs" both start with C.

By 2001, Grace and Aguilera were no longer with the Cubs, so Baylor anointed infielder Eric Young and catcher Joe Girardi (whose C had the potential for even more confusion, because C is also the shorthand symbol for "catcher").

Cincinnati Reds (two players)

Dave Concepcion's captain's C had a variety of sizes and placements over the years. pic.twitter.com/laVTBrUi4u — Paul Lukas (@UniWatch) May 22, 2017 The Reds gave Barry Larkin a captain's C that matched the team's cap logo. pic.twitter.com/gWYl2a6OI6 — Paul Lukas (@UniWatch) May 22, 2017

Since a captain's C was uncharted MLB territory back in the 1980s, the Reds were apparently undecided on the best protocol for wearing one. As a result, Concepcion wore Cs of varying sizes, usually on his left sleeve but sometimes on his upper-left chest.

Years later, beginning in 1997, the Reds took a more consistent approach for their other great shortstop who served as captain, Barry Larkin, who wore a small version of the team's distinctive wishbone-C logo on his upper-right chest during his captaincy. (Interestingly, when Concepcion was part of the team's opening day ceremonies in 2014, they gave him a current jersey with a Larkin-style C.)

New York Mets (two players)

Two Mets have worn the captain's C: Keith Hernandez and John Franco. pic.twitter.com/SuLLOPpG9h — Paul Lukas (@UniWatch) May 22, 2017

The Mets named Keith Hernandez as their captain and gave him a C in 1987, but he stopped wearing it when teammate Gary Garter was named co-captain in 1988. (Carter himself never wore the C -- just as well, given his surname and his position.) The Mets stayed C-less until 2001, when reliever John Franco was named captain and began wearing the designatory letter. More recently, third baseman David Wright has been the team's captain but has opted not to wear the C.

Boston Red Sox (one player)

Jason Varitek wore the captain's C from 2005 through 2011. pic.twitter.com/RGfCLulSP2 — Paul Lukas (@UniWatch) May 22, 2017

When the Red Sox re-signed catcher Jason Varitek to a new contract in 2005, they sweetened the deal by making him the team's captain and putting a C on his jersey, with GM Theo Epstein even making a big fuss over the C at the news conference announcing Varitek's new deal. He continued to wear the letter through the end of his career in 2011, making him MLB's last C-clad captain, at least for now. Along the way, he became the first and so far only player to wear the C in a World Series, in 2007 against the Rockies.

Kansas City Royals (one player)

Mike Sweeney wore the captain's C for the Royals from 2003-2007. pic.twitter.com/tXBOeOIKOs — Paul Lukas (@UniWatch) May 22, 2017

The mid-2000s were a rough period for the Royals -- on the field and in their uniform program -- so they did their best to promote Mike Sweeney, their most marketable player at the time. That included naming him captain and putting a C on his chest.

Houston Astros (one player)

Astros third baseman Enos Cabell wore a captain's C on his sleeve early in the 1985 season. pic.twitter.com/JjhjPWMRlx — Paul Lukas (@UniWatch) May 22, 2017

Early in the 1985 season, the Astros named infielder Enos Cabell as their captain and put a star-framed C on his left sleeve. As it turned out, Cabell's captaincy was also star-crossed, as he was traded to the Dodgers just a few months later. (Unfortunately, while several photos of the C-clad jersey itself are available, diligent Uni Watch research has so far failed to turn up a photo of Cabell wearing the jersey in a game. You can see evidence of the sleeve patch in this posed photo, but that's still not as good as a game shot. If you have access to such a photo, you know what to do.)

That's it -- almost. It's worth mentioning that MLB has sometimes named captains for the annual Home Run Derby, and those captains have sometimes worn a chest-borne C.

Captain's Cs in the Home Run Derby: Matt Kemp & Robinson Canó (2012); David Wright & Canó (2013); Troy Tulowitzki & Jose Bautista (2014). pic.twitter.com/S2Jcw3IOgU — Paul Lukas (@UniWatch) May 22, 2017

OK, that's it. Did we miss anyone? If so, please send your C notes here.

Would you like to nominate a uniform or uni element to be showcased in a future Friday Flashback installment? Send your suggestions here.

Paul Lukas realizes there's no need for an MLB captain to wear a C but still gets a kick out of seeing it, just for variety's sake. If you like this column, you'll probably like his Uni Watch Blog, plus you can follow him on Twitter and Facebook. Want to learn about his Uni Watch Membership Program, check out his Uni Watch merchandise, be added to his mailing list so you'll always know when a new column has been posted, or just ask him a question? Contact him here.