Misunderstand in what manner? The written form, the spoken form, or some minor meaning? The spoken "crack" has currency from around Yorkshire / Lancashire nor

Misunderstand in what manner? The written form, the spoken form, or some minor meaning? The spoken "crack" has currency from around Yorkshire / Lancashire north, meaning "news" / "gossip" / "comversation", it'd not be confused. South of there is isn't so common. Many folks in the northern part recognise the Irishised spelling, but not all. Have a read of the first paragraph of this, which (as far as GB goes) is a fair summary: https://en.wikipedia.org/wiki/Craic https://en.wikipedia.org/wiki/Craic