c1 is a quantity of liqueur coffee/coffee drink with a shot of liqueur/spirit j1.
See also: coffee making (=kafpra), Gaelic/Highland/Irish Coffee (=kotyjikryckafi), Bailey's Coffee (=kafrbeili), Monk's Coffee (=kafrbenediktine), Whisky Coffee (=ckafruiski), Russian Coffee (=kafrvo'otka), Karsk (=kafrkarska).