Hello fellow Super Mario World hackers! To make things clear I have no problem with swearing in general, but I hate excessive swearing. So should swearing be allowed or normal in hacks? Be sure to explain why instead of saying yes or no.
This topic has brought up interesting discussions in the past.
My thoughts are to do whatever you want though given the context of your level and the messages within them, it would be better to save it for appropriate times if you want the hack to look slightly professional.
Whether there are appropriate times is another question and the answer for that would be debatable. I never have seen an appropriate time for the use of them so I never included them in my hacks. You may be different. Being honest though, I cannot see why in most cases you would need to swear in hacks.
That is how I sum the whole situation up for me.