robot referer string of ../../

why would W3cRobot HEAD requests have relative referer strings?

[chinacat]

Our log has been showing lots of HEAD requests by W3CRobot/5.4.0 with various relative paths for the referer string. '../', '../../../'. Most requests get a 302, some get a 200. Is this normal when bots (or this bot) crawls the site?

[Lord Majestic]

Is this normal when bots (or this bot) crawls the site?

Its possible -- bots follow links and if somebody (most likely yourself) used relative links with "../../" and made mistake of having one too many "../", then bot which would resolve directory would have something like www.example.com/../index.php, which may still work since some (or even most) webservers would auto correct these attemps.