When writing in scientific english (as used in reports, technical papers and theses) ALL hyphens are treated as superfluous and deleted (well, at least the publications for which I prepared papers). As I recall however, the only exception is when listing an assemblage of mineral or chemical constituents eg ".....the Broken Hill lead-zinc-copper-silver deposit".

To be frank, hyphen deletion is not a bad way to go!! Try it in your next paper or report at work and you'll see that their removal often leads to more correct use of the language. Look at the hyphens in something you've written previously. Could you replace them with (a) a better word, (b) a full stop (ie "period"), (c) a comma or (d) could they simply be deleted with no effect on the sentence? (BTW MS Word just LURVS hyphens. I spend a lot of time NOT accepting those proffered by the spell checker!!)

The rules of scientific writing also rank adverbs as slovenly, incorrect and unnecessary! For instance, "...the process is usually accepted..." carries scientific oomph when "usually" is deleted. Guess that the rule forces one to write in the assertive rather than the passive. When I was working in the scientific world, the spell checker was always sent on a " *ly" search and destroy mission. The only one I used to let through was "only"!!

Since email has been around, I've taken up hyphen usage - it works for me as the written version of an afterthought or if I wish to make an aside in the middle of a sentence.

stales