Shady Char­ac­ters advent calendar 2025: RAINBOW FLAG


🏳️‍🌈
RAINBOW FLAG, aka Unicode code points (deep breath now) 0x1F3F3 0xFE0F 0x200D and 0x1F308.

RAINBOW FLAG contains multitudes. Multitudes of Unicode characters, that is, because ‘🏳️‍🌈’ is conjured into existence only if four other characters are placed in order, one after another.1 Nor is it the only such flag, or even the only such emoji; a surprisingly large number of emoji comprise two or more individual characters. By my count, the current version of Unicode admits of 2,760 such emoji2,3 out of 3,953 in total.4

These two-kids-in-a-trenchcoat emoji take many forms. There are those, such as HOT SPRINGS (♨️), which add a so-called variation selector to an older, monochrome symbol to signal that it should be rendered as an emoji. Certain abbreviations made of special “regional indicator” letters magically turn into country flags, such as Liechtenstein’s (🇱🇮), which comprises the regional indicators ‘🇱’ and ‘🇮’. Yet others marry a generic emoji (☝) to one of a selection of special skin-tone emoji (🏾️) to gain a more realistic appearance (☝🏾).2 And others are even more ambitious: this innocuous emoji (👩🏽‍❤️‍💋‍👩🏻) is made up of no fewer than four others (‘👩🏽’, ‘❤️’, ‘💋’ and ‘👩🏻’), not to mention that some of those four emoji are also made up of more than one individual character. Oh, and it has a sprinkling of special, invisible “joiner” characters, too.3

That there are so many emoji like this is at least partly because Unicode’s emoji subcommittee got bored of having to formally standardise every last emoji that crossed its desk.5 From 2015 onwards, the consortium started to lean on composite emoji as a way to quickly add new symbols to the emoji repertoire. RAINBOW FLAG arrived in 2016 as just such a character, comprising WAVING WHITE FLAG (🏳︎), RAINBOW (🌈), a variation selector to turn ‘🏳︎’ into ‘🏳️’ and a joiner character to glue the whole thing together.6 Hooray!

And then iPhones started crashing.7

A computer science student named Preston Petrie had worked out that a particular series of characters, similar but not identical to those inside RAINBOW FLAG, would cause the iPhone’s text processing engine to fail, and fail hard.8 The offending string looked like this: “🏳️0🌈”, with a ‘0’ interposed between the constituent parts of the RAINBOW FLAG. Remove that ‘0’ and everything was fine; leave it in, and any iPhone which received the string would freeze and then crash.9

A slew of media coverage ensued, but Apple moved quickly to get ahead of the story. Just a few days later, the company pushed out an update to the iPhone’s operating system to fix the bug10 and the furore soon died down. Yet the fact remains that for a time, a broken emoji was enough to break an iPhone. It’s easy to forget how bewilderingly complex our computers, smartphones and software are — and, correspondingly, how brittle they can be, too. And every now and again, a rainbow flag comes along to remind us.


1.
Davis, Mark. “L2/16-183:/Rainbow/Flag/Emoji”. Unicode Consortium, July 19, 2016.

 

2.
Unicode.org. “Emoji-sequences.Txt”. Accessed November 13, 2025.

 

3.
Unknown entry 
4.
Emojipedia. “Emoji Statistics”. Accessed November 13, 2025.

 

5.
Davis, Mark, Peter Edberg, and . “L2/15-252:/Unicode/Customized/Emoji/(UCE)/Proposal”. Unicode Consortium, n.d.

 

6.
Emojipedia. “🌈 Rainbow Emoji”. Accessed November 14, 2025.

 

7.
Gibbs, Samuel. “Prank crashes iPhones with rainbow emoji messages”. The Guardian, sec. Technology.

 

8.
Petrie, Preston. “Reckless Rainbow Bug”. preston159.com.

 

9.

 

10.

 

Shady Char­ac­ters advent calendar 2025: SPARKLES


SPARKLES, aka Unicode code point 0x2728.

If you spend even a modest proportion of your time online, you have almost certainly come across the SPARKLES emoji (✨). It’s a cheery and versatile symbol, and it is increasing found outside emoji’s usual habitat of text messages and social networks. Of late, in fact, SPARKLES has taken on a new gig that promises to significantly boost its profile, if not its popularity: ‘✨’ is now closely associated with that most divisive of technologies, AI.


Per Emojipedia, the SPARKLES emoji rode high throughout 2020 as the third most common emoji on Twitter after only ‘😂’ and ‘😭’. Keith Broni, Emojipedia’s editor-in-chief, attributed the emoji’s popularity to a rise in its use as a ✨whimsical✨, ✨magical✨ or ✨ironic✨ marker. Broni drew a comparison between this general pattern and the use of italics for the same purposes.1

Yet this temporary spike in popularity (‘✨’ was trending downwards by the end of 2020) was surely not enough to explain what happened next. As reported by Jazper Lu in the Wall Street Journal, in 2021 an “AI marketing” company named Jasper used the SPARKLES emoji in a marketing video — and from there, if indeed that was ground zero for the AI-sparkles fad, the practice spread like an airborne pathogen.2 By 2023, with a new wave of AI hype fuelled by a novel class of machine-learning algorithms called “transformers”, Spotify, Google, Zoom and OpenAI were all using ‘✨’ as a signifier for anything and everything connected to AI.3

Why did these titans of the tech world converge on ‘✨’? Lest you be deceived into imagining that the great and the good of the tech industry are any different to the rest of us, the answer is this: they couldn’t think of anything better. Lu cited “design and marketing executives” who claimed they had chosen the symbol simply because everyone else seemed to be making the same choice.2 This isn’t necessarily a bad reason — after all, if our various different computing devices employ conventions such as ‘🔍’ to mean “search”, or ‘💾’ for “save”, they are that much easier to use — but it doesn’t exactly speak to an industry which has scaled the heights of inspiration.

Groupthink aside, I do wonder if there is another reason for SPARKLES’ adoption as an AI mascot, and a ironic reason at that.

The basic properties of an emoji, such as its name, appearance, and numeric code point, are open to all. Although the Unicode Consortium claims copyright in its specifications, website, and other documents,4 it is nevertheless free and legal to build a computer system or typeface that makes use of Unicode’s work. Indeed, the internet of today would not work without Unicode’s accommodating approach to intellectual property: too many web pages and emails would arrive on our screens with unintelligible text and broken characters.

My thesis, then, is that the SPARKLES emoji’s lack of legal encumbrance makes it a tempting and low-risk choice. Google can use ‘✨’ to mean “AI”; Facebook can use ‘✨’ to mean “AI”; Microsoft can use ‘✨’ to mean “AI”; and they need not — indeed, cannot — waste each other’s time or money arguing in court over who owns it. I have no idea whether this is true or not (appropriately enough, Google’s Gemini chatbot didn’t know either), but it seems fitting that a legally charmed icon should become the symbol of a technology built on a foundation of voracious copyright infringement.


1.

 

2.
Lu, Jazper. “How the Sparkles Emoji Became the Symbol of Our AI Future”. Wall Street Journal, sec. Tech.

 

3.

 

4.
“Unicode Terms of Use”. Accessed November 9, 2025.

 

Shady Char­ac­ters advent calendar 2025: THUMBS UP


👍
THUMBS UP, aka Unicode code point 0x1F44D.

If the onsen emoji (♨️) and the hamburger (🍔) show us the nuts and bolts of how emoji work, THUMBS UP (👍) shows us how we, emoji’s users, put our own stamp on them. That’s because ‘👍’ is a chameleon and a provocateur, with meanings that can vary widely depending on how old you are and where you use it.


Like many of the most common emoji, THUMBS UP was inherited from Japan’s competing emoji sets and was standardised only in 2010.1,2 Yet unlike many of its peers, ‘👍’ had a non-emoji counterpart right from the start.

Facebook’s “like” button was that counterpart, an innocuous user-interface control which debuted in February 2009, and which which was normally rendered as a blue-tinted thumbs-up gesture.3 The company had been working on a “like” button since 2007,4 and, although emoji at the time were still mostly confined to Japan, many in the tech industry knew of emoji and were working on them in one capacity or another. It’s tempting to speculate, if not to state definitively, that Facebook’s thumbs-up button could easily have been inspired by the ‘👍’ which would soon make it way into the world at large.

There’s a lot to be said about the “like” button itself (and indeed, a lot has been said about it5,6,7,8), but in the interest of getting to the point, I’d like to look specifically at what it has done to the ‘👍’ emoji. Because with fifteen years of both “like” buttons and emoji under our belts, making use of the prima facie simple THUMBS UP emoji has become anything but straightforward.

With the caveat that this is my own personal opinion, it seems plain that the “like” buttons which litter social media and messaging applications, most of which ape Facebook’s simple thumbs-up, have cheapened the corresponding emoji. (A slew of recent opinion pieces seem to agree: “The unbearable rudeness of the thumbs up emoji”;9 “Thumbs up to the season of ambivalence”10 “Gen Z Have Cancelled The Thumbs Up Emoji And Here’s Why You Should Worry”11.) By making it trivially easy to acknowledge a message with a cursory ‘👍’, the ubiquity of the “like” button has cursed its emoji counterpart with a significant gravitas shortfall.

The result is that in 2025, the ‘👍’ survives mostly within environments that are inhospitable to irony. Corporate chat systems such as Microsoft Teams are one; earnest social networks popular with older people, such as Facebook, are another. In places such as these, a ‘👍’ conveys a meaning close to its real-world inspiration: yes, I will attend your meeting. Yes, I like your pictures from Disneyland Paris. But in other contexts, a ‘👍’ is not a good thing. It is the calling card of a desperately outmoded correspondent,12 or a symbol of assent so blasé as to shoot straight past agreement and hit passive aggression instead. Sure. Whatever.9

Like ‘😂’, ‘👍’ is a convincing data point in the ongoing argument over whether we should think of emoji as a language: they can certainly be as confusing, as contradictory, and as elusive as any word.


1.
Scherer, Markus, Mark Davis, Kat Momoi, Darick Tong, Yasuo Kida, and Peter Edberg. “L2/10-132:/Emoji/Symbols:/Background/Data”. Unicode Consortium, April 2010.

 

2.
The Unicode Standard, Version 6.0 - Archived Code Charts. Mountain View: The Unicode Consortium, 2010.

 

3.
Pearlman, Leah. “I Like This”. Facebook Note. Facebook.

 

4.
Unknown entry 
5.
Roosendaal, Arnold. “Facebook Tracks and Traces Everyone: Like This!”. SSRN Scholarly Paper. Rochester, NY: Social Science Research Network, November 30, 2010. https://doi.org/10.2139/ssrn.1717563.

 

6.
Levordashka, Ana, Sonja Utz, and Renee Ambros. “What’s in a Like? Motivations for Pressing the Like Button”. Proceedings of the International AAAI Conference on Web and Social Media 10, no. 1 (2016): 623-626. https://doi.org/10.1609/icwsm.v10i1.14768.

 

7.
Chin, Chih-Yu, Hsi-Peng Lu, and Chao-Ming Wu. “Facebook Users’ Motivation for Clicking the ‘Like’ Button”. Social Behavior and Personality: An International Journal 43, no. 4 (May 24, 2015): 579-592. https://doi.org/10.2224/sbp.2015.43.4.579.

 

8.
Eranti, Veikko, and Markku Lonkila. “The Social Significance of the Facebook Like Button”. First Monday, May 28, 2015. https://doi.org/10.5210/fm.v20i6.5505.

 

9.
Strimpel, Zoe. “The unbearable rudeness of the thumbs up emoji”. The Spectator (blog).

 

10.

 

11.

 

12.

 

Shady Char­ac­ters advent calendar 2025: HAMBURGER


🍔
HAMBURGER, aka Unicode code point 0x1F354.

In most ways, the HAMBURGER emoji is quite boring. It’s been around since emoji’s Japanese heyday, when it appeared on phones from all of Japan’s big cellphone networks, and it was one of the first emoji to be adopted for use in the wider world.1 Early documents show that ‘🍔’ was intended to represent both hamburgers specifically (ハンバーガー, or hanbaagaa) and fast food in general (ファーストフード, or fuaasutofuudo)2 — although its modest place in the emoji rankings, coming in at only 355th most popular in 2021,3 suggests that neither sense is particularly compelling. To put it another way, and to see emoji’s very long tail in action, HAMBURGER is used 677 times less often than ‘😂’, the most common emoji.

Why, then, am I writing about ‘🍔’? Well, for two reasons.

First is because HAMBURGER provides an object lesson in how emoji are not really standardised, at least not in the way you might expect. Back in 2017, when Google refreshed the visual appearance of all its emoji, the slice of cheese on the ‘🍔’ somehow migrated from its rightful position atop the burger to under it,4 prompting not a little online surprise.5 Google CEO Sundar Pichai, who, it should be noted, earned $200,000,000 that same year,6 publicly promised to fix the position of the cheese on a pixelated hamburger:

Will drop everything else we are doing and address on Monday:) if folks can agree on the correct way to do this!

And indeed, Pichai was as good as his word. The cheese was soon restored.7

That “burgergate” had come about at all was because neither Google nor anyone else truly controls what emoji look like. The Unicode Consortium, which gives each emoji its unique name and number, provides examples of how each one should be designed, but it has no way to enforce those suggestions. This is why Facebook’s emoji can look subtly different to Microsoft’s, and Microsoft’s to Snapchat’s, and so on. And furthermore, this is why Google, the first big Western company to embrace emoji, can put the cheese in the wrong place in the ‘🍔’.

The second reason to take note of the burger emoji is because its mid-table position in the emoji hierarchy has a practical significance. The set of emoji we can use on our phones and computers isn’t fixed. The same Unicode Consortium which manages the emoji lexicon invites proposals for new symbols, and each year, a lucky few are given the official seal of approval. One of the criteria for deciding which new emoji to approve is their expected level of usage — and that is where HAMBURGER comes in. Although its popularity is little more than a rounding error when compared to the most common emoji, ‘🍔’ sits roughly at the midpoint, or median, of emoji popularity: about half of all emoji are more popular, and about half are less popular.8 HAMBURGER is a helpful, beefy barometer for how popular an emoji needs to be before Unicode’s emoji subcommittee will take it into consideration.

The humble ‘🍔’ has a lot to teach us about how emoji work.


1.

 

2.
Scherer, Markus, Mark Davis, Kat Momoi, Darick Tong, Yasuo Kida, and Peter Edberg. “L2/10-132:/Emoji/Symbols:/Background/Data”. Unicode Consortium, April 2010.

 

3.
Daniel, Jennifer. “Emoji Frequency”. Unicode.

 

4.

 

5.

 

6.

 

7.

 

8.
Davis, Mark. “L2/19-082:/QID/Emoji/Proposal”. Unicode Consortium, March 28, 2019.

 

Shady Char­ac­ters advent calendar 2025: HOT SPRINGS


♨️
HOT SPRINGS, aka Unicode code points 0x2668 and 0xFE0F.

You would be forgiven for wondering what, exactly, this emoji (♨️) is meant to represent. Well, if the title has not already given the game away, I will tell you: this is the HOT SPRINGS emoji,1 and in emoji terms at least, it is positively antediluvian. Not only that, but ‘♨️’ gives us a peek behind the Unicode curtain — Unicode being the consortium, and the eponymous standard, which define how computing devices encode text.

The emoji that Unicode first added to their computerised character set in 2010 came from a variety of sources. Chief among them were Japan’s big three mobile phone networks: NTT, KDDI and Softbank.2 But pipping emoji into Unicode was a different collection of Japanese symbols. ARIB, the industry body for Japan’s TV and radio networks,3 had its own lexicon of symbols for TV news programmes, weather reports and more, and among those symbols was this one, ‘♨︎’, standing for the onsen, or hot springs, on which Japan’s traditional bath houses were built.4

Unicode is not a democracy, exactly, but the consortium accepts suggestions from other organisations and even members of the public on which characters should be added to its set. In 2007, then, a Michel Suignard had proposed to add ARIB’s symbols, including ‘♨’, to better support Japanese users.5 But Unicode already had an onsen symbol. In fact, it had had one since Unicode version 1.0, published way back in October 1991.6

Now, it’s not entirely clear to me why this should be the case. Unicode 1.0 was Frankensteined together from a number of earlier character sets, including two from Japan, but neither one of them contained an onsen character.7,8 ‘♨︎’ was a common cartographic symbol at the time,9 which may have been enough for Unicode to give it the nod, but that is pure supposition on my part. Not every character’s journey into the Unicode standard is documented, and the onsen symbol is every bit as mysterious as the interrobang (‽) in this respect.


So, to recapitulate: in 1991, for reasons unknown, a certain Japanese cartographic symbol (♨︎) made the cut for the initial version of Unicode standard. Its utility was reaffirmed in 2007 by its presence in a collection of Japanese broadcasting symbols also to be added to the standard.

Then, in 2010, came emoji. And it turned out that not only was ‘♨’ used on maps and on TV, but also that all three of Japan’s big cellphone carriers had a HOT SPRINGS emoji in their respective sets.2 End of story, right? Our onsen symbol has reached its final form.

Well, not quite. When Unicode added a host of emoji in 2010 it was obvious that they would have to be drawn in colour — but what of those, such as ‘♨︎’ which already existed as black-and-white symbols? We’re accustomed, these days, to emoji’s colourful appearance, but in the late 2000s, when emoji were still taking tentative steps out of Japan and into the rest of the world, text was very much a monochrome prospect. The Unicode Consortium didn’t quite know how to handle the problem, writing that:

Because many characters in the core emoji sets [overlap] with Unicode characters that originally came from other sources, there is no way […] to tell whether a character should be presented using an “emoji” style; that decision depends on context.10

You’re on your own, in other words. For a handful of years, these problematic characters were left up to those companies and organisations which translated Unicode’s abstract numeric “code points”* into concrete glyphs — the Googles, Apples, and Facebooks of the world, not to mention sundry type designers. In the confusion, some symbols were rendered as colourful emoji and others as sober monochrome icons.11

Finally, late in 2011, the consortium made some behind-the-scenes technical adjustments to allow certain characters to be rendered either in black and white or in colour;12 ‘♨︎’ and ‘♨️’ were given their own distinct appearances, and the onsen emoji was born.


I hope this has given you some insight into how emoji made their way onto our smartphones and computers, and how fraught their journey has been — and yet it’s worth noting that even tracing the evolution of the ‘♨️’ in some detail barely scratches the surface of that process. Whenever you type a ‘❤️’ or a ‘😭’, spare a thought for the programmers, language experts, and type designers who made it possible.


1.
Emojipedia. “♨️ Hot Springs Emoji”. Accessed October 31, 2025.

 

2.
Scherer, Markus, Mark Davis, Kat Momoi, Darick Tong, Yasuo Kida, and Peter Edberg. “L2/10-132:/Emoji/Symbols:/Background/Data”. Unicode Consortium, April 2010.

 

3.

 

4.

 

5.
Suignard, Michel. “L2/08-077R2:/Japanese/TV/Symbols”. Unicode Consortium, March 11, 2008.

 

6.
“Code Charts”. In The Unicode Standard, Version 1.0. The Unicode Consortium, 1991.

 

7.
CyberLibrarian. “JIS X 0208コード表”. Accessed November 10, 2025.

 

8.
CyberLibrarian. “JIS X 0212コード表(全コード)”. Accessed November 10, 2025.

 

9.
ゼンリンオンラインショップ. “地図から散歩”. Accessed November 10, 2025.

 

10.
“Symbols”. In The Unicode Standard, Version 6.0.

 

11.
Davis, Mark. “L2/13-207:/Which/Characters/Should/Have/Emoji-Style/by/Default?”. Unicode Consortium, October 30, 2013.

 

12.

 

*
For instance, ‘♨︎’ is represented by the hexadecimal number 0x2668.