How to get any character in the Gnome
If you have a system running Gnome (say Ubuntu), then you can enter any unicode character by its code by pressing Ctrl-Shift-U <hexadecimal code> <Enter> .
The already mentioned technique with Compose allows you to enter a very wide range of characters, but still not all.
It is clear that remembering codes is more difficult than “Compose - - -”, but for most characters there is no other way than launching a charmap and copying from there. After a couple of copies of the desired characters, their codes are usually remembered, and can be entered from the keyboard. This saves me a lot of effort.
(If you have known this information for a long time, do everyone a favor, and keep silent.)
The already mentioned technique with Compose allows you to enter a very wide range of characters, but still not all.
It is clear that remembering codes is more difficult than “Compose - - -”, but for most characters there is no other way than launching a charmap and copying from there. After a couple of copies of the desired characters, their codes are usually remembered, and can be entered from the keyboard. This saves me a lot of effort.
(If you have known this information for a long time, do everyone a favor, and keep silent.)