I am designing a search form where the user has to indicate if the field is required or optional, this will affect the way the query is built. For example if the user marks the field as required, in the query it would be an AND and if the user marks the field as optional in the query it would be OR.
I am thinking & and || as icons to represent them, but I think the users have not enough technical knowledge to know what it means. First thing I came up with was an asterisk (*) icon for required but I couldn't figure out for optional.
What do you suggest?