We all know that moderators can be recognized anywhere (except chat) by their diamond (♦︎︎︎) symbol by their screen name.

What was the design choice behind using the diamond, as opposed to something else, like the FontAwesome shield, like in Discourse? Or [M] like Reddit? Or a differently-colored name, like on Chat?

Is there some sort of written (or unwritten) history behind the diamond icon that we all know and love?

  • 8
    A heart would be highly in-appropriate. They are not elected for the love ;)
    – rene
    Sep 9, 2016 at 6:36
  • 10
    Just to note that mods have a differently coloured name (blue) in chat instead of having a diamond... Sep 9, 2016 at 6:43
  • This is a very interesting question, not sure why it was downvoted. I've three diamonds myself, and I have no idea why the symbol was chosen.
    – yannis
    Sep 9, 2016 at 10:26
  • I do believe at one point the community development team had a "phi" symbol. Not sure what happened to it. Sep 9, 2016 at 11:14
  • 1
    @JourneymanGeek PSI, not "phi". Here is a full screenshot since it's deleted. and the link to the relevant blog post that is mentioned there: joelonsoftware.com/items/2011/05/26.html and as for what happened to it: meta.stackexchange.com/questions/257699/… Sep 9, 2016 at 17:55
  • oops. Pointy trident thing? Its all greek to me ;p Sep 10, 2016 at 15:33
  • 13
    You can't always tell the difference visually, but some moderators actually have cubic zirconia.
    – Adam Lear StaffMod
    Sep 12, 2016 at 23:18

2 Answers 2


I don't have any insider knowledge but the diamond looks like pretty much the only satisfactory option if the design criteria were for a Unicode symbol (for ease of implementation and insertion into text usernames), that was widely supported across browsers in 2008, is bold and stands out clearly against text, and doesn't have confusing technical or other meanings:

  • Stack Overflow was launched in 2008 when things like icon fonts and font-face weren't common, and browser support was a more difficult problem than it is now. Firefox didn't support font face until 2010, for example. So, the choices would be limited to widely supported Unicode characters, else browsers would turn them into ?s or empty squares.
  • If you look at a list of widely supported Unicode characters from the days of HTML4 (alternate links are available in the comments if this link doesn't work, that properly old-school page has different geographic mirrors... haven't seen those since the '90s), there are really very few (♠, ♣, ♥, and ♦, possibly •), that meet the following criteria:
    • Bold and stands out clearly next to a username.
    • Doesn't have a technical or other meaning that would cause confusion. ¶ is a paragraph symbol, † would look like a footnote or religious symbol, and ⊕, ⊗, ⋠ and ∇ all have technical meanings in mathematics.
  • Of these, ♦ is the simplest and has least potentially confusing connotations. ♥ wouldn't really fit the tone, ♠ has associations with death and (usually bad) luck, and ♣ is a more visually complex symbol and looks like it might have a deeper meaning, e.g. it could be mistaken for an Irish shamrock. • is a bit weeny.

♦ however, is just a simple, reliable, eye-catching mark.

As for why not a text string like [M], diamonds are forbidden in usernames to prevent fake moderators, so presumably it was felt that reserving one rarely-used Unicode symbol from usernames was more elegant and less obtrusive than banning an arbitrary string of common characters like [M]. The diamond is also much more visually distinct than [M].

  • 13
    This pretty much captures it: performance, ubiquity, and an idiom that needs less explanation than a ☠ skull and crossbones ☠ . Sep 9, 2016 at 15:43
  • 1
    The link to the widely-supposed characters page appears to be 404'd.
    – Kaz Wolfe
    Sep 9, 2016 at 16:39
  • @KazWolfe are you sure? It works fine for me? The site seems to have some weird mirroring system going on, maybe try stanford.library.sydney.edu.au/symbols/entities.html ("Australia"), seop.illc.uva.nl/symbols/entities.html ("Netherlands") or plato.stanford.edu/symbols/entities.html ("USA")? Sep 9, 2016 at 16:57
  • @user568458 The mirrors work, but not the link in the answer itself. Caching, maybe?
    – Kaz Wolfe
    Sep 9, 2016 at 19:36
  • All the links work for me. I'd guess it's a geographical thing, maybe different links don't work in different locations. Mirrors used to make sense... in the 90s... I see your location is "dev/null", maybe that's why it's getting lost :-) Sep 9, 2016 at 20:26
  • 1
    I keep reading this as "Unicorn symbol" and wonder how that would look in place of a diamond.
    – Jamal
    Sep 10, 2016 at 1:12
  • @Jamal: Something like this. Sep 10, 2016 at 6:00

I don't think Jeff really spent that much time when deciding to use the diamond character.

But from the top of me head here are some possible reasons, in case he did give it some thought:

  1. Diamond is the strongest natural material. It implies power and toughness.
  2. Diamond is rare. Not just anyone can have one, or in this case, become a moderator.
  3. The diamond symbol/character is easy to spot and catches the eye.
  • And using an icon font (i.e FontAwesome) is probably overkill when you can just use a unicode character
    – Cai
    Sep 9, 2016 at 8:35
  • 5
    @Cai especially when FontAwesome was released long after Stack Overflow was launched. :) Sep 9, 2016 at 10:09
  • 2
    ITT: Real diamonds aren't rare at all. Their rarity is induced entirely by artificial scarcity.
    – Magisch
    Sep 9, 2016 at 11:30
  • @Magisch Yeah, we know who did it.
    – EKons
    Sep 9, 2016 at 12:10

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