WW1 uniforms...fur coats

simple question for ya`s all...i been watching a docu on WW1(the western front mainly,and its a british uniform)..and every docu on it i see lately there is always some1 in the group with a fur tunic on..white/cream fur..hip length..cutoff at the arms...every unit seems to have 1 of thes guys...could any body plz tell me what they/unit/job they where meant for???

much appreciated

plz dont say do a google coz i already done what i thought was a good seach and i cant find any units mention of this fir tunic

thx again

Its somethign to keep you warm, unfortunately they tended to freeze up and men thought they had frozen up. To free them they had to break the coats.