No symbol
Encyclopedia
The no symbol is a circle
with a diagonal line
through it (running from top left to bottom right), surrounding a pictogram used to indicate something is not permitted. The no symbol is usually colored red.
The Unicode code point for the prohibition sign (also called the no symbol) is
, which means that it appears on top of the character before it, so putting d⃠ will show d⃠. (Note: This will only appear if the characters exists in an available font.) It also appears in the Webdings
and Wingdings 2 fonts.
According to the ISO standard
(and also under a UK
Statutory Instrument
), the red area must take up at least 35% of the total area of the sign within the outer circumference of the "prohibition sign". So 35% of everything within the outer edge of the "no symbol" must be the symbol itself. Additionally, for printed signs under the UK rules, the width of a "no symbol" is set at 80% the height of the area it is printed to.
By analogy, the sign is used in public places to refer to prohibited actions not having to do with traffic:
It is also used on packages sent through the mail, and sealed boxes of merchandise that is sold in stores. Using a graphical symbol is useful when the item must be handled by people who understand different languages as it is transported. For example:
In product documentation, this may be accompanied by drawings of the product being threatened by the prohibited items: for instance, a cartoon of a floppy disk
being menaced by horseshoe magnets.
It is also used on clothing, linens, and other household products to indicate the care, treatment or cleaning of the item. For example:
Also, many companies use the "prohibition sign" when describing the services they offer, e.g. an insect deterrent spray brand symbol showing the "prohibition sign" over a mosquito. The Ghostbusters
logo is a fictional example of this.
.
In 2002, ISO 3864
-1 was published (a revision of a standard first published in 1984). The introduction includes language on the need for using as few words as possible to convey information.
ISO 3864
-1 sets the rules for the color and shape of safety signage, as well regulating the incorporation of text according to viewing distance and sign size. The range of color and shape defined in this standard for the "prohibition symbol" or "no symbol" is defined as "a prohibition surround shape (red circular band with a red slash going from the upper left to the lower right) over the top of a black graphical symbol."
Since the standard is not published freely (ANSI
sells it for USD $104, while ISO sells it for CHF 102,00) and many examples seen in public diverge from the standard, many symbols and public signs using it have not actually been based on the official standard, but instead on inexact copies or interpretations of signs or symbols seen by each graphic artist. This has led to wide variations in color and dimensions. The most common variations seen are brighter reds than specified in the standard and either a much thinner width for the line and slash, or about the right dimensions but using the same width for the slash as the circle (the standard specifies a width that is 80% as wide as the circle). For example, compare :Image:No smoking symbol.png (a non-compliant representation) with :Image:ProhibitionSign.svg (a representation drawn using the ISO standard).
In the UK, a filled blue circle (with no white inner circle) is used for positive signs, e.g. the wearing of a helmet on a building site, or the fact that a pathway is for pedestrians and cyclists. The 'no' symbol does not always have the 'slash' across it; in all traffic uses other than no turn, European 'no' signs are illustrated just with the prohibited action circled in red. An exception to this is the "No stopping" or "clearway" variant, this is illustrated with a red circle with a blue background and two diagonal 'slashes' forming an X. However according to the UK highway code signs with red circles are mostly prohibitive, and classifies these signs as "signs giving orders" rather than prohibition signs.
Circle
A circle is a simple shape of Euclidean geometry consisting of those points in a plane that are a given distance from a given point, the centre. The distance between any of the points and the centre is called the radius....
with a diagonal line
Diagonal
A diagonal is a line joining two nonconsecutive vertices of a polygon or polyhedron. Informally, any sloping line is called diagonal. The word "diagonal" derives from the Greek διαγώνιος , from dia- and gonia ; it was used by both Strabo and Euclid to refer to a line connecting two vertices of a...
through it (running from top left to bottom right), surrounding a pictogram used to indicate something is not permitted. The no symbol is usually colored red.
The Unicode code point for the prohibition sign (also called the no symbol) is
U+20E0;, Combining Enclosing Circle Backslash ( ⃠). It is a combining characterCombining character
In digital typography, combining characters are characters that are intended to modify other characters. The most common combining characters in the Latin script are the combining diacritical marks ....
, which means that it appears on top of the character before it, so putting d⃠ will show d⃠. (Note: This will only appear if the characters exists in an available font.) It also appears in the Webdings
Webdings
Webdings is a TrueType dingbat font developed in 1997 and included in all versions of Microsoft Windows since that time. Most of the glyphs have no Unicode character equivalents.-New York City:...
and Wingdings 2 fonts.
According to the ISO standard
International Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...
(and also under a UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
Statutory Instrument
Statutory Instrument
A Statutory Instrument is the principal form in which delegated or secondary legislation is made in Great Britain.Statutory Instruments are governed by the Statutory Instruments Act 1946. They replaced Statutory Rules and Orders, made under the Rules Publication Act 1893, in 1948.Most delegated...
), the red area must take up at least 35% of the total area of the sign within the outer circumference of the "prohibition sign". So 35% of everything within the outer edge of the "no symbol" must be the symbol itself. Additionally, for printed signs under the UK rules, the width of a "no symbol" is set at 80% the height of the area it is printed to.
Uses
The "prohibition" symbol is used on traffic signs, so that drivers can interpret traffic laws quickly while driving. For example:-
No left turn -
No U-turn -
No parking
By analogy, the sign is used in public places to refer to prohibited actions not having to do with traffic:
- No smokingSmoking banSmoking bans are public policies, including criminal laws and occupational safety and health regulations, which prohibit tobacco smoking in workplaces and/or other public spaces...
(with icon of a lit cigarette) - No littering (with icon of person littering)
- No swimming (with icon of swimmer in water)
It is also used on packages sent through the mail, and sealed boxes of merchandise that is sold in stores. Using a graphical symbol is useful when the item must be handled by people who understand different languages as it is transported. For example:
- Breakable; do not drop
- Keep away from magnetic fields
In product documentation, this may be accompanied by drawings of the product being threatened by the prohibited items: for instance, a cartoon of a floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...
being menaced by horseshoe magnets.
It is also used on clothing, linens, and other household products to indicate the care, treatment or cleaning of the item. For example:
- Do not iron
Also, many companies use the "prohibition sign" when describing the services they offer, e.g. an insect deterrent spray brand symbol showing the "prohibition sign" over a mosquito. The Ghostbusters
Ghostbusters
Ghostbusters is a 1984 American science fiction comedy film directed by Ivan Reitman and written by Dan Aykroyd and Harold Ramis. The film stars Bill Murray, Dan Aykroyd, Sigourney Weaver, Harold Ramis, and Rick Moranis and follows three eccentric parapsychologists in New York City, who start a...
logo is a fictional example of this.
International standards
While the "prohibition sign" has been so widely used in advertising and promotions that now any variation of the design flipped left or right or varied in hue is considered acceptable and recognized by the general public as a symbol of prohibition, it is still governed by local and international standards. The standard definition of the no symbol comes from the International Organization for StandardizationInternational Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...
.
In 2002, ISO 3864
ISO 3864
ISO 3864 specifies international standards for safety symbols. These labels are graphical, to overcome language barriers.The corresponding American standard is ANSI Z535, which is incompatible with the ISO standard....
-1 was published (a revision of a standard first published in 1984). The introduction includes language on the need for using as few words as possible to convey information.
ISO 3864
ISO 3864
ISO 3864 specifies international standards for safety symbols. These labels are graphical, to overcome language barriers.The corresponding American standard is ANSI Z535, which is incompatible with the ISO standard....
-1 sets the rules for the color and shape of safety signage, as well regulating the incorporation of text according to viewing distance and sign size. The range of color and shape defined in this standard for the "prohibition symbol" or "no symbol" is defined as "a prohibition surround shape (red circular band with a red slash going from the upper left to the lower right) over the top of a black graphical symbol."
Since the standard is not published freely (ANSI
Ansi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....
sells it for USD $104, while ISO sells it for CHF 102,00) and many examples seen in public diverge from the standard, many symbols and public signs using it have not actually been based on the official standard, but instead on inexact copies or interpretations of signs or symbols seen by each graphic artist. This has led to wide variations in color and dimensions. The most common variations seen are brighter reds than specified in the standard and either a much thinner width for the line and slash, or about the right dimensions but using the same width for the slash as the circle (the standard specifies a width that is 80% as wide as the circle). For example, compare :Image:No smoking symbol.png (a non-compliant representation) with :Image:ProhibitionSign.svg (a representation drawn using the ISO standard).
Variants
In contrast, a green circle with no line through it may be used as a Yes symbol, or the "anti prohibition sign", indicating that the activity represented inside the circle is permitted, but this is not official. It is mainly used to give advice, rather than to say what must be done.In the UK, a filled blue circle (with no white inner circle) is used for positive signs, e.g. the wearing of a helmet on a building site, or the fact that a pathway is for pedestrians and cyclists. The 'no' symbol does not always have the 'slash' across it; in all traffic uses other than no turn, European 'no' signs are illustrated just with the prohibited action circled in red. An exception to this is the "No stopping" or "clearway" variant, this is illustrated with a red circle with a blue background and two diagonal 'slashes' forming an X. However according to the UK highway code signs with red circles are mostly prohibitive, and classifies these signs as "signs giving orders" rather than prohibition signs.
See also
- Federal Highway AdministrationFederal Highway AdministrationThe Federal Highway Administration is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two "programs," the Federal-aid Highway Program and the Federal Lands Highway Program...
- ISO 3864ISO 3864ISO 3864 specifies international standards for safety symbols. These labels are graphical, to overcome language barriers.The corresponding American standard is ANSI Z535, which is incompatible with the ISO standard....
- List of international common standards
External links
- UK legislation regarding health and safety signs, The Health and Safety (Safety Signs and Signals) Regulations 1996 (SI 341)Statutory InstrumentA Statutory Instrument is the principal form in which delegated or secondary legislation is made in Great Britain.Statutory Instruments are governed by the Statutory Instruments Act 1946. They replaced Statutory Rules and Orders, made under the Rules Publication Act 1893, in 1948.Most delegated...
- UK legislation regarding road signs
- Working drafts for UK road signage
- Printable US signage using the no symbol