Is the second period necessary after an abbreviation?
Which one of the following is correct?
only in the continental U.S.A. For all other countries...
only in the continental U.S.A.. For all other countries...
I am not sure if I need two periods after "U.S.A." or just the one.
The general consensus seems to be that there is never an acceptable use of two sequential periods. A period at the end of an abbreviation is adequate punctuation when a period would end the sentence naturally. If any punctuation mark other than a period is needed, that may be added. Similarly, within a sentence, as when a comma would be appropriate, that may be added.
III. only in the continental USA. For all other countries...
avoids the awkward lack of consistency of (1) and the awkward style of (2) - and is correct
(The United States of America (USA or U.S.A.)... : http://en.wikipedia.org/wiki/United_States