No symbol

The general prohibition sign (official name, according to ISO 7010), also known as a no symbol, no sign, circle-backslash symbol, nay, interdictory circle or universal no, is a red circle with a red diagonal line through it (running from top left to bottom right), completely enclosing a pictogram to indicate something is not permitted. The symbol is sometimes black instead of red, when color is not available. The general prohibition sign (official name, according to ISO 7010), also known as a no symbol, no sign, circle-backslash symbol, nay, interdictory circle or universal no, is a red circle with a red diagonal line through it (running from top left to bottom right), completely enclosing a pictogram to indicate something is not permitted. The symbol is sometimes black instead of red, when color is not available. The Unicode code point for the prohibition sign is U+20E0, Combining Enclosing Circle Backslash (   ⃠ ). It is a combining character, which means that it appears on top of the character immediately before it. Thus, putting ♪ ⃠ ∞ ⃠ will display an eighth note inside the prohibition sign, followed by the infinity symbol inside the prohibition sign: ♪ ⃠  ∞ ⃠. It also appears in the Webdings and Wingdings 2 fonts. There is also a prohibition sign emoji located at U+1F6AB NO ENTRY SIGN (?), which does not combine with anything. According to the ISO standard (and also under a UK Statutory Instrument), the red area must take up at least 35 percent of the total area of the sign within the outer circumference of the 'prohibition sign'. Therefore, 35 percent of everything within the outer edge of the 'no symbol' must be the symbol. Additionally, for printed signs under the UK rules, the width of a 'no symbol' is set at 80 percent the height of the area to which it is printed.