my understanding of crackships is that they do not have to be crossovers, no. crossover shipping can and mostly be comprised of crackships, but you can crackship two characters within the same body of work. A common type of crackship is two characters that never speak or so much as exist in the same room as each other but that you think will have fun chemistry if they did.

all that being said I don’t really have many regular ships much less crack ones. Never was a very strong shipper I just go with the flow yaknow? if you can convince me the ship is good then I will clap and go Yay