Common Unicode Characters and Compose sequences

Unicode characters I use commonly, and which have no key mapped by default.
Note Unicode code points (Unicode “codes”) can be introduced in GNOME easily with CTRL+Shift+U followed by the hex code.

• En dash: U+2013 ⇒ –
• Em dash: U+2014 ⇒ —
  • Also Compose + -,-,- (Compose + 3 dashes)
• Figure dash: U+2012 ⇒ ‒ (same width as a digit in fonts with same-width digits: «1‒2‒3»)
• Horizontal bar: U+2015 ⇒ ― (hard to distinguish from em dash in most fonts/font sizes)

Ref: http://en.wikipedia.org/wiki/Dash

U+391 = Α, U+392 = Β, U+393 = Γ, …

U+3b1 = α, U+3b2 = β, U+3b3 = γ, …

• Full table at wikipedia: http://en.wikipedia.org/wiki/Greek_alphabet#Greek_in_Unicode [As of 2010-03-21]

U+2254 ⇒ ≔

U+225F ⇒ ≟

Unicode name QUESTIONED EQUAL TO, source: http://www.w3.org/TR/MathML2/bycodes.html
MathML: equest, questeq

See also: http://en.wikipedia.org/wiki/Unicode_mathematical_operators

• Guillemets: U+ab, U+bb ⇒ « » (HTML: laquo and raquo)
  • Also Compose, <, < and Compose, >, >
  • Also AltGr + z and AltGr + x (X-Window, layout-dependant?)
• Typographical double: U+201c, U+201d ⇒ “ ” (HTML: ldquo and rdquo)
  • Also Compose, <, “ and Compose, > ”
  • Also AltGr + v and AltGr + b (X-Window, layout-dependant?)
• Typographical single: U+2018, U+2019 ⇒ ‘ ’
  • Also Compose, <, ' and Compose, >, '
  • Also AltGr + Shift + v and AltGr + Shft + b (X-Window, layout-dependant?

Refs:

• http://en.wikipedia.org/wiki/Guillemets#Typing_.22.C2.AB.22_and_.22.C2.BB.22_on_computers
• http://en.wikipedia.org/wiki/Quotation_mark#Typing_quotation_marks_on_a_computer_keyboard

Obviously they're the same width in fixed fonts.

• Non-breaking (HTML's &nbsp;): U+a0 ⇒ [ ]
• Hair space: U+200a ⇒ [ ]
• Thin space: U+2009 ⇒ [ ] (HTML: thinsp)
• En space/Nut: U+2002 ⇒ [ ] (width of 1 en, half em), (HTML: ensp)
• Em space/Mutton: U+2003 ⇒ [ ] (width of 1 em), (HTML: emsp)
• Figure space: U+2007 ⇒ [ ] (same width as a digit in fonts with same-width digits: «1 2 3», non-breaking)

• Space Symbol: U+2420 ⇒ ␠
• Open box symbol: U+2423 ⇒ ␣

Ref and more types of spaces: http://en.wikipedia.org/wiki/Space_%28punctuation%29#Table_of_spaces

• Permille: U+2030 ⇒ ‰
  • Also Compose + %,o (Compose, Percent, letter O)
• Permyriad: U+2031 ⇒ ‱

• Copyright: U+a9 ⇒ ©
  • Also Compose, c, o and Compose, c, 0 (Compose, letter C, letter O or number 0)
• Trademark: U+2122 ⇒ ™
  • Also Compose, t, m
• Registered trademark: U+ae ⇒ ®

U+20a7 ⇒ ₧ (looks awful in most fonts, not in all)

Ref: http://en.wikipedia.org/wiki/Spanish_peseta#Symbol