Abbreviations consist of the first letters of a word but not the last letter:

  Mon   Vic   Rev Jones

Increasingly the trend is not to put a full stop after the last letter, although ‘no.’ (short for number) is a notable exception (to avoid confusion with ‘no’).

A contraction consists of the first and last letters of a word:

  Mr  Qld   Rd   Dr Morton

Again, no full stop is needed after the last letter.

Acronyms are strings of initial letters pronounced as a word:

  OPEC   TAFE   AWOL

Initialisms, like acronyms, are strings of initial letters but they are not pronounced as a word:

  OMG   BTW   NSW

Plural forms of shorted words and phrases do not need an apostrophe:

  FAQs   MPs   PhDs

If the shortened form is unlikely to be familiar to readers and is used several times in a document, write the words in full the first time, followed by the shortened form in brackets, and then in shortened form for subsequent mentions:

  The University Student Advisory Board (USAB) voiced their concerns … Last year USAB indicated that ninety students …