Mr or Mr.; BC or B.C.? abbreviations, acronyms, and initialisms.

I have noticed a trend recently towards writers dropping the period on abbreviations. No longer is it Mr. or Dr. but Mr and Dr; P. D. Smith has become PD Smith and so forth. I have wondered if this is a trend, laziness, or self-correcting software gone mad.

I decided to go to the source — the Chicago Manual of Style.

According to the Chicago Manual of Style:

• an acronym is a term based on the initial letters and read as a single word (scuba, NASA, AIDS);
• an initialism refers to terms read as a series of letters (UBC, NHL, HTML);
• and a contraction (not the apostrophe kind) is an abbreviation that includes the first and last letters of the full word (Mr., amt., Dr.).

So that seems straightforward enough but, of course, there are exceptions. What about XML (extensible markup language), or JPEG, or ©, or FAQ?

According to Grammar Girl:

Finally, there's no strict rule about putting periods after each letter in an acronym or initialism. Some publications put periods after each letter, arguing that because each letter is essentially an abbreviation for a word, periods are necessary. Other publications don't put periods after each letter, arguing that the copy looks cleaner without them, and that because they are made up of all capital letters, the fact that they are abbreviations is implied.

 The Chicago Manual of Style, however, recommends the following:

1. Dr., a.m., Mr., Ms., vol., rear Adm., Esq. — essentially abbreviations that end in a lowercase letter should have a period.
2. Given names should use periods: P. D. Smith; unless, and here it comes, it replaces the whole name: JFK.
3. No periods for abbreviations that appear in full capitals even when there are lowercase letters within the abbreviation. Here are some examples to help clarify things: CEO, BA, US, BC, PhD.

As always, it depends on the style guide of the publication. Traditional publications will use U.S.; the British and French omit the periods on contractions (Dr, Mr). The US military omits periods for the official forms of its ranks but there are variations within branches. SSG for an army staff sergeant; SSgt for the air force and marines.

Are you thoroughly confused now?

There are more rules to do with science and technology, biblical abbreviations, units, business, and so forth.

How do you feel about it all? Is it something that you are diligent about? Are you thwarted in your attempts by your software program indicating you have grammatical errors? Do you think it matters?