Some types of challenges require submission that produce constant output and, as such, forbid the solutions from taking input of any kind.
That presents a problem for languages like sed, which execute code for each line of input, so they downright refuse to do anything if STDIN is empty.
On one hand, if we apply the same rules to all languages, sed simply won't be allowed to compete. On the other hand, excluding a language altogether seems undesirable.
Should a language that requires input to do anything be allowed to take input, even if all other languages are not?
What should that input be?
What should happen in cases like this one, where an exemption from the rule would simplify the task at hand?