Content-Filter JS code

Hi guys,
a question about the content-filter: it’s not clear to me what to do if the label returns 1.
Reading the docs:

If the filter returns 0 or 1, you should accept that as the filter’s outcome

So do I have to accept it and go on with the program, or manage it as the previous examples?
What value threshold should I check against, for value=1?

Thanks in advance.