The document defines acronyms as abbreviations formed from the initial letters of words in a phrase, with each letter pronounced separately. It distinguishes between acronyms, which are pronounced as words, and initialisms, which are pronounced letter-by-letter. Examples are provided of different types of acronyms, including those containing non-initial letters or a mixture of initial and non-initial letters. The use of acronyms has increased with text messaging. Styles of writing acronyms include all capital letters or small capital letters for those over three letters.