Saying something 'ist kreig' means it is extreme, or 'cool' in a black-metal-fan sort of way. Black metal fans often use it jokingly if they are talking about something that is far from extreme or cool in a black-metal-fan sort of way.

It’s an acronym standing for Can’t Remember A Fucking Thing. It’s usually used to describe embarrassment at being unable to remember someone (CRAFT moment); going onstage as the lead in the latest theatrical performance and your mind goes completely blank (CRAFT situation); the next morning after a night when you got pissed as a fart and woke up in bed cuddling a traffic cone and a string of fairy lights wound round your prick.

"is lame". Popular within the geriatric community.

A play on the German "is krieg" a derivative of "war" which means "it's cool"; however the alternate spelling creates new meaning.