a diacritic chording system uses a single standard keyboard layout to generate diacritical characters used , for example , by latin - based languages or languages based on a roman character set , providing a universal keyboard the key combination required to select a diacritic is consistent , independent of the language the user is typing . the diacritic chording system uses chording to obtain characters modified by diacritics , i . e ., diacritical characters . the key combinations in the diacritic chord are chosen in such a way to aid memorization by positional association of the keys or by logic association of the keys within the diacritic chord . the use of a combination of positional association and logical association eliminates conflicts in mapping diacritics for different languages . the diacritic chording system also provides a screen overlay as a mnemonic to illustrate which diacritic chords provide the desired diacritical character .