Discussion Groups / English Usage / May 2009

No, the common practice is to use singulars in this case.

"His files were indexed by name, by address, by phone number..." even
though each file entry had a different name, address, and number.

You must have changed your focus between writing the subject line and
writing the question, because neither form you gave used an article.
A, an, and the, iirc.

Howeever I am bothered because there are "by"s in front of the first
two choices and not the remaining three.  Maybe there's a good reaso;n
for this but if they are all the same, probably better to have one
"by" for all five, or five "by"s.    Although frankly in speech, the
way you have it is quite likely, for a reason that is hard to
describe, maybe more likely than the 1 or 5 "by"s I'm recommending.