It is considered a letter of the alphabet.

In Vietnamese and Spanish, it also used to be considered a letter for collation purposes but this is no longer common.

This digraph was considered a single letter in Spanish orthography, called elle.

Й was not officially considered a separate letter of the alphabet until the 1930s.

"They don't have to forward a letter because an e-mail is considered a letter."

It is neither considered a vowel, nor even a diacriticized letter.

Sh is not considered a distinct letter for collation purposes.

It is considered a separate letter, and is the 14th letter of the alphabet.

It was formerly considered a distinct letter, but is no longer.

In both norms, nh is not considered a distinct letter.