One-letter, two-number identifiers are keyed by the alphabetical letter.

Researchers have employed shapes and alphabetical letters to represent this illusion as well.

The symbols ESRB uses are stylized alphabetical letters meant to indicate the game's suitability.

But alphabetical letters are traditionally used in the U.S. to designate subsections of statutes.

The problem with spelling on a telephone touch pad, however, is that a single number corresponds to three alphabetical letters.

The different positions were represented by alphabetical letters, except the dieses which had special signs not unlike the tyronic letters used by Boethius:

I guess it got started with two alphabetical letters, O and K. It means... agreement.

In Shelton's shorthand system every consonant was expressed by an easy symbol which sometimes still resembled the alphabetical letter.

The different neighbourhoods are almost clearly divided by the starting alphabetical letter of every street.

Despite having the starting alphabetical letter too, Heerevelden is, together with Witbrant, the only neighbourhood with this.