While some abbreviations and acronyms require periods, many do not. Here are some guidelines for deciding whether or not to use periods.

1. Identify the source of the abbreviation or acronym.

2. Do not use periods in any of the following:

   • an acronym or abbreviation based on initial letters
   • a two-letter state abbreviation
   • a compass point
   • a technical abbreviation

   Example: Does this computer have DVD-R capacity?

   Example: This file is 4 MB, so it will take some time to download over a modem operating at 56 kps.

   Example: Please send a CD to my office (10 University Drive, Duluth, MN 55812).

   However, periods are often retained in abbreviations that stand for degrees or titles.

   Example: This program was designed by Prof. Walt Kovacs, Ph.D.

Remember: Except for degrees and titles, most abbreviations and acronyms do not need periods.

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