Training t5 small, custom training task and dealing with unknown input

Hi I have been working on training t5-small to do a cusgom task for example Endorsement A: Fraudulent Claims Clause – SA200 and convert it to Fraudulent Clause – SA200; This is a very contrived example but hopefully you get the idea. So after training the model is outputting im getting is quite good. The problem I have come across is what the model does if it gets a pievce of text it doesnt understand - “Hi my name is t5.” I would like the model to output nothing. Instead T5 attempts a translation task instead. i would really like to it output nothing in this case. Whati have done so far 1. I played around with appending “summarize” to the input text. But i dont think this is the correct task as it “kind of” worked but removed more text from the original input than i would of liked Any ideas of how i can handle input that doesn’t match with the specific task i am doing? Thank you.