I think when searching for 'apache', net-www/apache should be the first hit, and other packages with apache in the name should come next, follow by mod_* which just have it in their description.
not sure what searching algorithm we're using. marduk?
The search is made pretty much the same as the -s and -S flags in the emerge command. All searches are regular expressions. So even doing an "emerge -S apache" the apache package shows up 8th or so. If you are, for example, specifically looking for the "apache" package, then your search string would be "^apache$"