By James L. Franklin
   I was lucky enough to find Garner's usage  guide on sale on the publisher's Web site last year and bought it for personal use, but I find it has become one of  the three reference books
I use most frequently on the job.

   It is, most of all, a guide to American usage and does that by distinguishing British and American forms when  the differences are relevant to a usage decision. For example, in the entry on  ``encumbrance, incumbrance, cumbrance,'' Garner writes: ``The preferred spelling of this
word, meaning `a claim or liability that is  attached to property and that may lessen its value,' is encumbrance in both AmE  and BrE. Cumbrance is a needless variant.''

   Needless variants, which are rife in technical  writing, suggest to the reader that the writer is somehow distinguishing  cases when the intention may be only to vary vocabulary by using different  forms of the same word. The effect if such departures is to confuse the  reader. Better, more explicit writing avoids such variants, which Garner suggests should be dropped from the language. In this, Garneradopts the views of H.W. Fowler and credits him for it.

   What I like most about Garner is that his guide shows the mind of a good writer, more than a disciplinarian. His treatment of punctuation is worth the price of the book. For example, he deals with  the fuzzy thinking behind use of the slash, more formally known as the virgule (an increasing problem in corporate PR, influenced, I speculate, by our latter-day familiarity with the frequent use of the slash in computer terms).  The slash is sometimes used as a substitute for per (miles/hour) or for the conjunctions and and or.  Other times it suggests a disjunction (the novel/novella distinction), Garner writes.  All those uses can be replaced by a better alternative, Garner says, noting that the slash is largely absent from first-rate writing.

I'm also delighted by his clear explanation of  comma usage, for example stressing the need for commas between the clauses of a compound sentence, with the exception of the case in which the  subject of the two clauses is the same (and is not repeated).  I see that comma between clauses omitted most frequently when the conjunctions or and for, but also left out before the conjunction and, as well.  Yet, I  frequently see as a sort of breathing pause in a so-called compound  predicate.  To use Garner's example: "They did the spring cleaning, and then had a  picnic."  The comma should be deleted, but if writer or editor thinks the  sentence needs the pause in a longer sentence, the solution is to add a comma  and the subject, not a lonely and otherwise extraneous comma.
Garner's book deserves a place around the rim.

James L. Franklin is a copy editor on the night desk at The Boston Globe.  He has been a writer and  editor at the Globe since 1971 and has covered religion, the environment, and the suburbs