"may" vs "can"

[Jane Bergen <janeb -at- IADFW -dot- NET>]

Sue Heim writes:

       How do you feel about using "may" or "can" in docs and marketing
       collaterals. For example, I really don't like the following sentence
      (this is from a brochure of ours):

     "Author reprint request cards may be generated, and references can be
      output in a variety of formats."

Admittedly, it's hard to tell from one or two sentences, but this excerpt
has problems beyond the "can" or "may" issue:

1)  WHO is going to generate these cards? Output these references? The
passive voice always makes me stop and ask, "is this something I (as
reader/user) am supposed to do, or does the computer (or widget or whatever)
do it?

2) "author reprint request cards" is a very long string (3 adjectives + 1
noun). It's always best to break these down whenever possible and practical.

3) "may" means "it could happen" but "can" means someone or something will
MAKE it happen. In other words the idea of deliberation. For example, "if
you fail to do xx, then you may break yy." But, "you can do xx...." seems to
imply  that you can deliberately choose to do it without implying anything
about further result.

Just two cents.

 Jane Bergen
 janeb -at- iadfw -dot- net
"The difference between the right word and the almost right word
 is the difference between lightning and the lightning bug" (Mark Twain)