Pension Credit - temporary absences abroad?

Understanding that PC can be paid when you are temporarily absent from GB…“for up to 13 x weeks if your absence is unlikely to exceed 52 weeks”, what is the requirement, if any, to advise the PS of your impending absence if likely to be for the max 13 weeks. I note on AA award letters that you are supposed to advise the DCS of any absences of more than 4 x weeks but am not aware of a similar PC requirement. 

Also, if you return after a 13 x week absence, is there any PC regulation that states you must then be domicile back in UK for a specific period of time before a further absence? Or what is the maximum period of absence from the UK for PC purposes before you fail to meet “habitual residence” conditions.  Neither of these enquiries relates to travelling abroad for the purposes of medical treatment.

Many thanks