Symbols for zero
The modern numerical digit 0 is usually written as a circle, an ellipse or a rounded square or rectangle.
Glyphs
In most modern typefaces, the height of the 0 character is the same as the other digits. However, in typefaces with text figures, the character is often shorter (x-height).
Traditionally, many print typefaces made the capital letter O more rounded than the narrower, elliptical digit 0.[1] Typewriters originally made no distinction in shape between O and 0; some models did not even have a separate key for the digit 0. The distinction came into prominence on modern character displays.[1] The digit 0 with a dot in the centre seems to have originated as an option on IBM 3270 displays. Its appearance has continued with Taligent's command line typeface Andalé Mono. One variation used a short vertical bar instead of the dot. This could be confused with the Greek letter Theta on a badly focused display, but in practice there was no confusion because theta was not (then) a displayable character and very little used anyway. An alternative, the slashed zero (looking similar to the letter O except for the slash), was primarily used in hand-written coding sheets before transcription to punched cards or tape, and is also used in old-style ASCII graphic sets descended from the default typewheel on the Teletype Model 33 ASR. This form is similar to the symbol , or "∅" (Unicode character U+2205), representing the empty set, as well as to the letter Ø used in several Scandinavian languages. Some Burroughs/Unisys equipment displays a digit 0 with a reversed slash. The opposing convention that has the letter O with a slash and the digit 0 without was advocated by SHARE, a prominent IBM user group,[1] and recommended by IBM for writing FORTRAN programs,[2] and by a few other early mainframe makers; this is even more problematic for Scandinavians because it means two of their letters collide. Others advocated the opposite convention,[1] including IBM for writing Algol programs.[2] Another convention used on some early line printers left digit 0 unornamented but added a tail or hook to the capital O so that it resembled an inverted Q (like U+213A ℺) or cursive capital letter-O ().[1] Some fonts designed for use with computers made one of the capital-O–digit-0 pair more rounded and the other more angular (closer to a rectangle). The TI-99/4A computer has a more angular capital O and a more rounded digit 0, whereas others made the choice the other way around.
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The typeface used on most European vehicle registration plates distinguishes the two symbols partially in this manner (having a more rectangular or wider shape for the capital O than the digit 0), but in several countries a further distinction is made by slitting open the digit 0 on the upper right side (as in German plates using the fälschungserschwerende Schrift, "forgery-impeding typeface"). Sometimes the digit 0 is used either exclusively, or not at all, to avoid confusion altogether. For example, confirmation numbers[3] used by Southwest Airlines use only the capital letters O and I instead of the digits 0 and 1, while Canadian postal codes use only the digits 1 and 0 and never the capital letters O and I, although letters and numbers always alternate.
Other
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Usual appearance of zero on seven-segment displays
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Unusual smaller appearance of zero on seven-segment displays
On the seven-segment displays of calculators, watches, and household appliances, 0 is usually written with six line segments, though on some historical calculator models it was written with four line segments. The international maritime signal flag has five plus signs in an X arrangement.
Zero symbols in Unicode
- U+0030 0 DIGIT ZERO
- U+0660 ٠ ARABIC-INDIC DIGIT ZERO
- U+06DF ۟ ARABIC SMALL HIGH ROUNDED ZERO
- U+06E0 ۠ ARABIC SMALL HIGH UPRIGHT RECTANGULAR ZERO
- U+06F0 ۰ EXTENDED ARABIC-INDIC DIGIT ZERO
- U+07C0 ߀ NKO DIGIT ZERO
- U+0966 ० DEVANAGARI DIGIT ZERO
- U+09E6 ০ BENGALI DIGIT ZERO
- U+0A66 ੦ GURMUKHI DIGIT ZERO
- U+0AE6 ૦ GUJARATI DIGIT ZERO
- U+0B66 ୦ ORIYA DIGIT ZERO
- U+0BE6 ௦ TAMIL DIGIT ZERO
- U+0C66 ౦ TELUGU DIGIT ZERO
- U+0C78 ౸ TELUGU FRACTION DIGIT ZERO FOR ODD POWERS OF FOUR
- U+0CE6 ೦ KANNADA DIGIT ZERO
- U+0D66 ൦ MALAYALAM DIGIT ZERO
- U+0DE6 ෦ SINHALA LITH DIGIT ZERO
- U+0E50 ๐ THAI DIGIT ZERO
- U+0ED0 ໐ LAO DIGIT ZERO
- U+0F20 ༠ TIBETAN DIGIT ZERO
- U+0F33 ༳ TIBETAN DIGIT HALF ZERO
- U+1040 ၀ MYANMAR DIGIT ZERO
- U+1090 ႐ MYANMAR SHAN DIGIT ZERO
- U+17E0 ០ KHMER DIGIT ZERO
- U+1810 ᠐ MONGOLIAN DIGIT ZERO
- U+1946 ᥆ LIMBU DIGIT ZERO
- U+19D0 ᧐ NEW TAI LUE DIGIT ZERO
- U+1A80 ᪀ TAI THAM HORA DIGIT ZERO
- U+1A90 ᪐ TAI THAM THAM DIGIT ZERO
- U+1B50 ᭐ BALINESE DIGIT ZERO
- U+1BB0 ᮰ SUNDANESE DIGIT ZERO
- U+1C40 ᱀ LEPCHA DIGIT ZERO
- U+1C50 ᱐ OL CHIKI DIGIT ZERO
- U+2070 ⁰ SUPERSCRIPT ZERO
- U+2080 ₀ SUBSCRIPT ZERO
- U+2189 ↉ VULGAR FRACTION ZERO THIRDS
- U+24EA ⓪ CIRCLED DIGIT ZERO
- U+24FF ⓿ NEGATIVE CIRCLED DIGIT ZERO
- U+3007 〇 IDEOGRAPHIC NUMBER ZERO
- U+3358 ㍘ IDEOGRAPHIC TELEGRAPH SYMBOL FOR HOUR ZERO
- U+A620 ꘠ VAI DIGIT ZERO
- U+A8D0 ꣐ SAURASHTRA DIGIT ZERO
- U+A8E0 ꣠ COMBINING DEVANAGARI DIGIT ZERO
- U+A900 ꤀ KAYAH LI DIGIT ZERO
- U+A9D0 ꧐ JAVANESE DIGIT ZERO
- U+A9F0 ꧰ MYANMAR TAI LAING DIGIT ZERO
- U+AA50 ꩐ CHAM DIGIT ZERO
- U+ABF0 ꯰ MEETEI MAYEK DIGIT ZERO
- U+FF10 ０ FULLWIDTH DIGIT ZERO
- U+1018A 𐆊 GREEK ZERO SIGN
- U+104A0 𐒠 OSMANYA DIGIT ZERO
- U+10D30 𐴰 HANIFI ROHINGYA DIGIT ZERO
- U+11066 𑁦 BRAHMI DIGIT ZERO
- U+110F0 𑃰 SORA SOMPENG DIGIT ZERO
- U+11136 𑄶 CHAKMA DIGIT ZERO
- U+111D0 𑇐 SHARADA DIGIT ZERO
- U+112F0 𑋰 KHUDAWADI DIGIT ZERO
- U+11366 𑍦 COMBINING GRANTHA DIGIT ZERO
- U+11450 𑑐 NEWA DIGIT ZERO
- U+114D0 𑓐 TIRHUTA DIGIT ZERO
- U+11650 𑙐 MODI DIGIT ZERO
- U+116C0 𑛀 TAKRI DIGIT ZERO
- U+11730 𑜰 AHOM DIGIT ZERO
- U+118E0 𑣠 WARANG CITI DIGIT ZERO
- U+11950 𑥐 DIVES AKURU DIGIT ZERO
- U+11C50 𑱐 BHAIKSUKI DIGIT ZERO
- U+11D50 𑵐 MASARAM GONDI DIGIT ZERO
- U+11DA0 𑶠 GUNJALA GONDI DIGIT ZERO
- U+16A60 𖩠 MRO DIGIT ZERO
- U+16B50 𖭐 PAHAWH HMONG DIGIT ZERO
- U+16E80 𖺀 MEDEFAIDRIN DIGIT ZERO
- U+1D2E0 𝋠 MAYAN NUMERAL ZERO
- U+1D7CE 𝟎 MATHEMATICAL BOLD DIGIT ZERO
- U+1D7D8 𝟘 MATHEMATICAL DOUBLE-STRUCK DIGIT ZERO
- U+1D7E2 𝟢 MATHEMATICAL SANS-SERIF DIGIT ZERO
- U+1D7EC 𝟬 MATHEMATICAL SANS-SERIF BOLD DIGIT ZERO
- U+1D7F6 𝟶 MATHEMATICAL MONOSPACE DIGIT ZERO
- U+1E140 𞅀 NYIAKENG PUACHUE HMONG DIGIT ZERO
- U+1E2F0 𞋰 WANCHO DIGIT ZERO
- U+1E950 𞥐 ADLAM DIGIT ZERO
- U+1F100 🄀 DIGIT ZERO FULL STOP
- U+1F101 🄁 DIGIT ZERO COMMA
- U+1F10B 🄋 DINGBAT CIRCLED SANS-SERIF DIGIT ZERO
- U+1F10C 🄌 DINGBAT NEGATIVE CIRCLED SANS-SERIF DIGIT ZERO
- U+1F10D 🄍 CIRCLED ZERO WITH SLASH
- U+1FBF0 🯰 SEGMENTED DIGIT ZERO
- U+E0030 TAG DIGIT ZERO
See also
- Arabic numeral variations § Slashed zero
- Regional handwriting variation § Arabic numerals
- Ø (disambiguation)
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Bemer, Robert William (August 1967). "Towards standards for handwritten zero and oh: much ado about nothing (and a letter), or a partial dossier on distinguishing between handwritten zero and oh". Communications of the ACM. 10 (8): 513–518. doi:10.1145/363534.363563. S2CID 294510.
- ↑ 2.0 2.1 Einarsson, Bo; Shokin, Yurij (2007-05-24). "Fortran 90 for the Fortran 77 Programmer". Appendix 7: "The historical development of Fortran. Archived from the original on 2017-02-28.
- ↑ "Check in for your Flight Reservation".