I know it's the compose key, and I set it to right Alt and I set the "3rd level" option to the Shift + Alt, but I can't figure out for the life of me for example how to do the copyright symbol, or the registered mark, or trademark symbol, etc. I try alt then c but I get č.

  • 1
    This very much depends on the keyboard layout you're using. Go to System → Preferences → Keyboard → Layouts to see which one you're using, and add it to the question. If you're lucky, you can answer your own question after clicking "Show" on your layout (for some, the special characters are visible there) Feb 11, 2011 at 8:29
  • The answer i marked correct seemed to work for me :) Feb 14, 2011 at 0:43

4 Answers 4


Compose key

Compose,o,c will produce ©.

You can view the combinations in your locale's Compose file, e.g.


For those without a compose key configured (it isn't by default). Go here for latest versions. On Ubuntu 12.04 the setting is hidden away at System > Preferences > Keyboard > Layout > Options... > Compose Key Position. I prefer to use the "menu" key as compose, but it's a matter of preference.

AltGr (Third-level modifier)

On a UK English layout, AltGr+Shift+c also produces ©.

The standard USA layout doesn't include many characters at the third level as US keyboards have a second Alt rather than AltGr.

The layouts "USA International (AltGr dead keys)" and "USA International" have © at AltGr+c. "USA International (AltGr dead keys)" would be better for most as the other turns the apostrophe into a dead key for the acute accent.

The Ubuntu documentation has a comprehensive list of Compose key sequences plus further info on Compose and AltGr.

  • 2
    I remember hearing about an alternative US layout that includes a bunch of third level chars (emulating AltGr). Does that exist? Feb 11, 2011 at 12:45
  • Ah yes, USA International does.
    – misterben
    Feb 11, 2011 at 12:55
  • +1 good and accurate answer. Adding the setting for the Compose key would make it even better: System > Preferences > Keyboard > Layout > Options... > Compose Key Position (in a basement disused lavatory with a sign on the door "beware of tiger" could they hide it better?)
    – msw
    Feb 11, 2011 at 13:05
  • Thanks so much! Is there a place i can learn all of these? Feb 14, 2011 at 0:49
  • English (Macintosh) also has a very rich selection of third-level chars, notably sensibly placed math/scientific chars (personal.crocodoc.com/oImDdk4). May 9, 2012 at 15:07

For an occasional unicode character there is always Ctrl+Shift+*unicode-value*
This allows you to type virtually all Unicoode charactesr... (basically all the public ones)

You can get any and all unicode values (Codepoints) from many places;
I find this one the most useful: fileformat.info characcter search

Just search for 'copyright' and take you pick..
The most relevant unicode symbol is


To enter it in a Gnome window (like here), just type: Ctrl+Shift+00a9
followed by a space .. use lowercase letters ("a" not "A")

  • ©

Here are a couple more. Just type Ctrl+Shift where you see U+,
and use lower case letters: a b c d e f


Here is a link for general interest (or boredom :)
A count of Unicode characters grouped by script

  • In KDE, Ctrl-Shift-U then release all keys, then type 00a9 and space.
    – Nick
    Apr 21, 2021 at 17:15

For searching-and-copying rare chars, this is invaluable:

$ sudo apt-get install unicode


$ unicode copyright
UTF-8: c2 a9  UTF-16BE: 00a9  Decimal: ©
Category: So (Symbol, Other)
Bidi: ON (Other Neutrals)

UTF-8: e2 84 97  UTF-16BE: 2117  Decimal: ℗
Category: So (Symbol, Other)
Bidi: ON (Other Neutrals)

Usually I don't care about the precise unicode properties, the recently added --terse flag helps. And once it's not so verbose, I don't want the default limit of 10 chars. So I usually call it with:

> unicode --terse --max=0 copyright

For the copyright symbol, try this page . [Actually, do what @misterben says in his terrific answer. I'll leave this link as a curiosity.]

As a generalized answer, if you are typing something odd that you do not often use, do a search for a word containing the character, and cut and paste.

For instance, on the Wikipedia Linguistics page , go to any of the languages listed on the left column. This solution also works for special characters with the correct search.

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