Calebaut cocoa butter callets

I make all natural skin care and use all food grade ingredients, cocoa butter being one of them...I am a cocoa butter connoisseur and love the stuff, I eat it use it in my baking and also make skin care with it... I ordered a 3kg tub of Callebauts cocoa butter for the first time, When I opened it, it was the tiny calletts I think they are called (look like chocolate chips without the tips), I am fine with all this, my question is this...after melting some I noticed it did not look just like my other melted cocoa butters, so I checked the label and it said may contain milk....what does this mean, does it or dosent it and does this mean I didnt get pure cocoa butter and what is the milk....milk powder? I thought I was getting pure cocoa butter...any info would be great. Thank you

From The Nut Shea Butters