What are task prefixes for all Conditional Generation Models?

I am currently fiddling around with different transformer architectures for summarization task, and I got curious as to what are task prefixes of pretrained Conditional Generation Models. I know T5’s prefixes and found this website pertaining to the same. But, I have not been able to find anything for Bart, Pegasus, ProphetNet etc. I know that if we are training the model from scratch, then we can have our own task prefixes. But, would like to know of pretrained models present on huggingface