Hi, whenever a request is sent to Wikipedia with the following header, the result is Error 403: User-Agent: W3C-checklink/4.1 [4.14] libwww-perl/5.803 The resulting document has a XHTML 1.0 Strict definition, but it is not valid XHTML 1.0 Strict - see http://topjaklont.student.utwente.nl/invalid.html and try to validate it. Why is Error 403 served at all? As for example www.sp.nl proves, W3C-checklink can obey robots.txt. It also sleeps one second between each request, so it does a fair job in throttling. What's the problem then? regards, Gerrit Holl. -- Weather in Twenthe, Netherlands 27/02 16:25: -3.0°C wind 6.3 m/s NNE (57 m above NAP) -- In the councils of government, we must guard against the acquisition of unwarranted influence, whether sought or unsought, by the military-industrial complex. The potential for the disastrous rise of misplaced power exists and will persist. -Dwight David Eisenhower, January 17, 1961