It is common the use of asterisk (*) to indicate required elements. I understand the use of explicit text is better than relying on symbols. So writing "required" or "optional" is more understandable than relying on some symbol.
I'm creating lists of elements characteristics for personal use. These are not forms, just text lists. Most (90% or more) of the elements I am listing will be required. So rather than indicate required elements I want to (only) indicate optional elements, which are the minority. I can use my own symbol and give it the optional meaning as my team will be the only ones reading the elements. But I was wondering if there is any convention of a symbol for optional fields/elements.
My question is related to lists of text, not forms. Although I think there might not really be much difference. As far as I understand it the required goes in the label anyway. Also, again, this will be for personal use.
So the question is if there is any symbol/way to represent optional elements. Either used as a convention (in some niche) or if someone has any suggestion.