Abbreviations and Contractions

The general rule is the use of a full stop when the word is an abbreviation:

Co.  Esq.  etc.  the Rev.

but not when it is a contraction (ends with the last letter of the word):

Mr  Dr  Pty  Ltd

Another way of putting it is that if the short form ends with the same letter as the word (doctor, Mister) omit the full stop.

Exceptions include metric weight and measures:

mm  sq m  kg

No. for number is another exception—though it is a contraction of numero, it takes a full stop.

Per cent should be spelled out (except in a statistical report or balance sheet) as two words, and though cent is an abbreviation of centum it does not take a full stop.

Generally speaking, full stops are omitted in abbreviations made up of initial letters (acronyms):

NHMRC
WA, ACT, etc.

An exception to this appears in this University’s official publications in which names of institutions are abbreviated after the names of members of staff. In this case, the Publications Unit currently follows the Commonwealth Universities Yearbook original style in which full stops have been retained:

A.N.U.
W.Aust. etc.

In ordinary text (where saving space is not essential) abbreviations such as ‘Prof.’ and ‘univ.’ are to be avoided. UWA is acceptable in some documents, although ‘this institution’ or ‘this University’ is often more appropriate in a formal report when wishing to avoid tedious repetition.