Any character with a hexadecimal code listed in KS C 5601 can be entered directly as follows. The KS C 5700 standard is supported by UTF-8 hexidecimal code. (The ko locale is used in the following example.)
The only keys that have any effect at this point are delete keys, letters a through f, numbers 0 through 9, and Control-X (which toggles hex mode off again).
Type the first three keys of the hex code of the character, for example a2dd, in the preedit area.
The screen appears as follows after the first three numbers are typed:
Type d.
The designated character is then displayed and automatically committed after the fourth number is typed:
Hex mode remains on until toggled off by Control-X.