Inappropriate Abbreviations

In informal writing, abbreviations are perfectly acceptable as long as the reader understands the meaning. In formal writing, though, abbreviations are only used if absolutely necessary. Here’s a list of abbreviations which are never acceptable in formal writing:

Days of the week and months of the year

Write Sunday, not Sun.

Write April, not Apr.

Nicknames and short forms of personal names

Write Susan, not Suze (unless that it her given name)

Write William, not Wm.

Geographical places

Write New York City, not NYC.

Write California, not Ca.

The United States of America (or possibly America), not U.S. or U.S.A.

Units of measurement when used in a sentence

Write miles, not mi.

Write grams, not g.

Write pounds, not lbs.

Short forms of words

Write Christmas, not Xmas.

Remember that some abbreviations are only acceptable in certain contexts: see BC, AD, a.m., p.m., No. and $*, and Latin Abbreviations.