How do I express the plural of a letter in writing?

Question

My last name has two occurrences of the letter "s" in it, so in speech I tell people all the time that it's spelled "with two esses". However I don't know how to express such a thing in writing. I can see half decent reasons for any of "s's", "S's", "ses", "Ses", "ss", "Ss", or "esses" . Which is/are correct?

Answer 1

The rule for forming plurals of singular words that already end in "s" is to add "es."

dress -- dresses

guess -- guesses

The same rule applies to Proper Nouns:

Mr. Jones -- The Joneses