If your grade school English teacher taught the same lessons as mine, you probably learned about the "optional comma" that you could use before the conjunction in a series of items.
If this is true, either of the following sentences would be correct.
the serial comma
CSI's Manual of Practice has a different view.
Strunk and White's Elements of Style agrees.
application of the rule
Well, what's the difference? The problem becomes apparent in more complex sentences. It is not unusual to find a list of pairs of items.
Using the "optional comma" rule, the sentence becomes:
The last four items now run together. This makes the sentence a little harder to read, but it can still be understood. After all, there is no confusion between faces and sides, right?
Let's look at another example. The "optional comma" rule says there is no difference between the following sentences.
Seen together, it is obvious that the first sentence requires one to provide water, and to provide electrical distribution equipment. The second sentence is ambiguous. It might mean the same as the first sentence, or it might require one to provide water distribution equipment and electrical distribution equipment.
If the second interpretation is desired, the following sentence is more easily understood, but still awkward.
What does the "optional comma" sentence look like?
Kind of a mess, isn't it? Use the serial comma - or your spec might become a killer.
keep it simple
The MOP also states that a sentence "should be constructed so the misplacement or elimination of a punctuation mark will not change the meaning."
Carried to its conclusion, this rule precludes the use of all but the most simple sentences. (Strict application would eliminate about ninety percent of the general conditions, and put a lot of attorneys out of work!) Proper use of commas, colons, and semicolons serves a useful purpose. Avoiding their use out of fear of misplacing them is equivalent to avoiding words with more than four letters.
On the other hand, there is great value in using simple sentences. Short, simple sentences are easy to understand and less likely to be misinterpreted. A short list of single items should not be a problem, provided the comma is used correctly. Longer lists and lists of groups of items would be better presented as subparagraphs. Not only is the list easier to read, but it serves as a checklist as well.
To read an on-line version of the 1918 edition of Elements of Style, go to http://sut1.sut.ac.th/strunk/. To get the current edition, which includes a new glossary of grammatical terms, a new Foreword by Roger Angell, and classic principles of English style, go to www.strunkandwhite.com/.
© 1996, 2002 Sheldon Wolfe, RA, CSI, CCS, CCCA
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