0 vs. O

aluminum's picture

Just a quick rant. When was it decided that digital type on a screen would no longer use the "slash-o" to represent a zero?

I'd like to petition typographers in general to bring back the slash-o numeral zero. It would save me countless hours trying to decipher passwords and user log-ins. Good typography is usually related clarity. Let's clarify our zeros and ohs!


Thomas Phinney's picture

Adobe has been putting in a slashed zero in all its new fonts for the last few years. However, it is generally not the default form, but an alternate (only accessible to apps that are OpenType savvy).


dezcom's picture

As Mr. Bill from the original Saturday Night Live used to say, "Oh, n-0-o-0-o-0-o-0!!!"

speter's picture

Clearly the Scandinavian lobby won. :-)

Si_Daniels's picture

>When was it decided that digital type on a screen would no longer use the "slash-o" to represent a zero?


Si_Daniels's picture

That was a guess. My feeling is the move occured during the transition from custom, often monospaced bitmap fonts (often but not always drawn by non-typedesigners) to outline fonts. Some supporting evidence here - http://www.algonet.se/~guld1/index_de.htm - many of these 'ripped' bitmap fonts include the slashed zero.

A. Scott Britton's picture

I agree. And it is about legibility; oftentimes the only way to distinguish between 0 and O is through the context of seeing them in use with other glyphs from the same set--this can't be good practice.

Maybe you should draft a manifesto to the effect that designers (who, ultimately, have the power to change or re-adopt such conventions) reclaim the slash-zero. I'd sign it (although, admittedly, a big reason why is because I really dig the art of the manifesto; I don't think it's done nearly enough nowadays).

Nick Shinn's picture

Lining figures are confusing in general:
3689 and 5S.

The best arrangement for passwords etc: full caps with old-style figures -- Georgia?

hrant's picture

> Clearly the Scandinavian lobby won.

I'm a sucker for explicit divergence for legibility, but the slashed zero seems too... brutal.
And yes, potentially confusable with the O-Slash! So maybe a nestled dot is better.

But then there's something else: this is a "deliberative" issue, meaning that when there's potential confusion the reader has all the time he needs to figure out if it's an Oh or a Zero. So if you diverge the glyphs in more subtle ways (like through height, width, or squareness) you can really solve the problem 95%, without "brutality".

A serious problem however is an old-style Zero that's too much like a lc oh. The usual solution -making it a "perfect" circle- is just pukey to me. So reversing the stroke contrast (which makes sense in the context of the numerals in general), or giving it weight only on one side, and/or using hybrid nums (taller than x-height) is better, I think.

> Georgia?

But the original Georgia nums (hybrids), not the later -tamed- ones.


as8's picture

I post this for the poster diggers like me & maman Mr. A. Scott Britton :-)

aluminum's picture

"So maybe a nestled dot is better."

The Scandinavians have a point, and I was actually thinking the same thing, HRANT. Perhaps a dot in the center of the zero is what we need.

"you can really solve the problem 95%, without "brutality"."

Well, the problem really only manifests itself when you're mixing letters of various cases with numerals. The common places this happens is in URLS (0sil8.org), Password/logins (Hol107L), software serial numbers, and programming languages. So, the problem is primarily online, where the subtle ways may simply not work.

The slash-zero was designed specifically for computer use (I think...) and I find it odd that it dissappeared while computer use was actually increasing.

Of course, there's also the l/1 issue, but we'll save that for another day...

dezcom's picture

Fabulous posters Alessandro

as8's picture

Tak, on jest bardzo piekny!

I have 0ne 0n-line n0w:

"Rice Is Life"
Index: www.aiap.it/asso/attivita/2004/wgd04/worlday0.htm

david_roughs's picture

Good question about the "slash-0".

I work at a library and trained myself to start slashing zeros for better legibility with call numbers. Though the dotted 0 does sound nicer.

The l/1 is still an issue though. And funny that it was mentioned, as I've just gotten back from a trip to Paris (Paris!), where I noticed the numeral 1 is almost always written as if it were an UC "A" minus the crossbar (and perhaps with a slightly shortened left leg). It took me a minute to decipher it, but it does seem to make a lot of legibility sense.

Actually, I was considering a post about just that. How common is the A-without-a-crossbar numeral one, and are there any fonts that use it?

David Roughs

dezcom's picture

and the crossbar through the z to distinguish it from a number 2

seg's picture

im not sure about something - when a reader sees a zero with a slash or a dot doesnt he still get it confused with the O? i mean, do people know that the slash/dot indicates a 0 and not an O?

im guessing that the zero & slash combination would be clear to most readers, but i dont think the dotted zero will be easily recognized. in their handwriting, some people slash their zeros.

anyway, i havnt seen alot of slashed or dotted zeros used around me, so maybe that kind of zero will confuse the reader even more.

and arent there also O's with dots inside them?

aluminum's picture

"do people know that the slash/dot indicates a 0 and not an O?"

Anyone that's used a computer in the 80s would. ;o)

Also, I've seen a lot of reference type people (librarians, etc.) use the slash-0 when handwriting. I still do that myself when it's an alphanumeric series.

Jonathan Clede's picture

I prefer the zero with a backslash to distinguish it from the scandinavian letter. And this is how I write it by hand.

boole's picture

I once entered 1 instead of 7 in the database at work (the handwriting wasn't very legible) and it caused a minor confusion with the accounts.

I've generally noticed that americans don't cross their 7s. Somebody told me that I write a canadian 7!? I always thought of it as an individual's idiosyncracy not really a culturaly influenced thing. Anybody else crosses their 7's?

Hrant was right that on a printed page it's not all that hard to tell zeroes from O's. But with handwriting, it's impossible to distinguish. (serial numbers are a real pain in the but in particular)

hrant's picture

I cross my "7", and my "z". It must be essentially cultural - what else? Although the "source motivation" is partly one of legibility. And I cross my zero too - not that anybody besides me reads my handwriting. Certainly not any Danes. :-)

BTW, many Japanese people actually cross their "D" too! To avoid confusion with the "O"/zero. This makes it potentially confusing with the Eth, but Iceland is pretty far from Japan...


ebensorkin's picture

I have always heard that a slashed 7 was 'continental'. This being said in an anglo-centric USA. What about a rerverse slash? That seems especially good to me somehow. FABRIZIO SCHIAVI likes it - sort of. He has a dot/slash.


dezcom's picture

His looks a bit too Theta like too me. This is a programers font so it may not be an issue. Programmers need the distinction between zero and O to be clear on screen so the Greek issue probably does not apply in this case.


hrant's picture

Slashing in general is continental - quite often the
"z" has it too, which can actually help it not be a 2.

I don't like the dot style myself, but it might actually
be less bad than the traditional slashed one, which can
be confused for the O-slash (like in Danish). I actually
like the reverse-slash one best.

> Programmers need the distinction between zero and O to be clear

We all need that, sometimes. Even in print. And even Greeks. :-)


dezcom's picture



ebensorkin's picture

I like the dot okay in print as long as it isn't disproportionate but I find that hinting it is a pain as you go down in size. I wonder if Fabrizio made his dot/slash so that it would be easier to hint into than a round dot would be.

riccard0's picture

Adobe has been putting in a slashed zero in all its new fonts for the last few years.

And because the slash isn’t confined to the counter, they all resemble Øs, rendering them useless.
By the way, I’m a proponent of the backslashed 0, like the one in the original Anonymous.

hrant's picture

That or with a dot in the middle.


riccard0's picture

Yes, Andale Mono features the dotted 0 (and, if I remember correctly, some fonts offer it as alternate along the slashed one), but maybe it’s because I was exposed to too much fantasy, I see it as a sort of Mason-like O… ;-)

ahyangyi's picture


Yes, Consolas offers dotted 0 and clean 0 as alternative versions of the slashed 0. It also has old-style figures.
Sadly, Visual Studio, the software which most likely being used together with Consolas, doesn't support these Opentype features.

quadibloc's picture

Indeed; computer screens used a slashed zero back when they used a 5 by 7 dot matrix to display monospaced characters using character generator circuitry. Even when a somewhat higher resolution was used on the IBM PC, zeroes were still slashed in DOS.

When they instead wrote characters that looked like type on a graphic screen (such as on the Macintosh, and then on PCs with Microsoft Windows, OS/2, GEM Desktop, or GeoWorks Ensemble) then a slashed zero would not be used.

Té Rowan's picture

Some Danes, at least, used the alashed zero where they would have used the (non-existing) Ø/ø. It is obvious in the Danish translation of Thom Hogan's CP/M handbook.

HVB's picture

Back when I was just learning Fortran programming in the late 50's, we were told to differentiate our sheets for the keypunch operators by slashing the letter O! It took a while to switch when later on, in another time and place, Zeroes were slashed.

- Herb

Birdseeding's picture

I was taught to put a line through q as well, is that also a "continental" thing?

mjr's picture

When I worked in a library while in college back in the 1980s, we had a typewriter with a large point size, specifically for making call-number labels for book spines. The 0 (zero) was full height, as were all the digits. The lower-case o was x-height. And the upper-case O had a loop at the top right, as if it were handwritten and was about to be connected to the next letter.

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