Web recognition

Its not really related to code, and more related to an algorithem.
(which will be implemented in perl)
my problem is as follows, given a website, for example, http://www.nokia.com,
how can I really determine whether its the manufacturer site (official
nokia's site...) or not? (for example, htttp://www.nokia-fans.com is
not, assuming there is something like that...).

The real problem arises when the manufacturer name does NOT
corresponds the site name, for example, manufactuere name : YTXT , and
website http://www.XXX.co.uk

any idea?