Learn English – Word for “only letters”


I am looking for a word that means "only letters A–Z", sort of like alphanumeric, but not numbers. The closest I got is alphabetic/alphabetical. The context is

Please enter a [word] string:

This is in a program I am making that doesn't work if anything other than A–Z is entered.

Best Answer

While the word you are looking for is indeed alphabetical, the only characters you allow are all letters — this excludes numbers, spaces, punctuation and special symbols like &.

Please enter only letters.

You could make it absolutely explicit with

Please enter only alphabetical letters.

Note that some languages include special characters like ß é ð and so on, which some users may well include in the definition of letter or alphabetical. You may need to exclude those explicitly too:

Please enter only unaccented alphabetical letters, A–Z or a–z.