Rejected abstract submitters still considered "authors" in Participants roles

Dear Indico Community,

My question regards the “Participants roles” list, in which authors of rejected abstracts are still displayed as “Author”.

Is there a way for me to redefine the role “Author” as authors of a) abstracts linked to a contribution only, or at least b) accepted abstracts, even if they are not linked to a contribution?

Thank you in advance.