Q.12 Undisplayable Characters

Your terminal may be unable to display some non-ASCII characters. Most non-windowing terminals can only use a single character set (use the variable default-terminal-coding-system (see section Q.9 Specifying a Coding System) to tell Emacs which one); characters which can't be encoded in that coding system are displayed as `?' by default.

Windowing terminals can display a broader range of characters, but you may not have fonts installed for all of them; characters that have no font appear as a hollow box.

If you use Latin-1 characters but your terminal can't display Latin-1, you can arrange to display mnemonic ASCII sequences instead, e.g. `"o' for o-umlaut. Load the library `iso-ascii' to do this.

If your terminal can display Latin-1, you can display characters from other European character sets using a mixture of equivalent Latin-1 characters and ASCII mnemonics. Use the Custom option latin1-display to enable this. The mnemonic ASCII sequences mostly correspond to those of the prefix input methods.