As far as I can see the changes to the Temporary Absence rules introduced the 4-week limit to students studying abroad – they now fall under 7(17D)… seems like they only qualify for a room from the date they return to the date they leave again (subject to the usual notification rules)
http://new.hbinfo.org/legislation/main-regulations/regulations/regulation-7-circumstances-which-person-or-not-be-treated-o
