es vs lowercase letters ... form the plural with an apostrophe and an s". The Oxford Style Manual on page 116 advocates the use of common sense.

es

noun

  • The name of the Cyrillic script letter С / с. 

lowercase letters ... form the plural with an apostrophe and an s". The Oxford Style Manual on page 116 advocates the use of common sense.

How often have the words es and lowercase letters ... form the plural with an apostrophe and an s". The Oxford Style Manual on page 116 advocates the use of common sense. occurred in a corpus of books? (source: Google Ngram Viewer )