So I started my search in the library catalogue looking for festivals in the middle ages and came upon a book about drama, acting and festivals titled Festivals and plays in late medieval Britain / Clifford Davidson, call number PR641 .D37 2007. After looking thought the table of contents I saw that it was mostly about playwrights and not the actual festivals. So I went back to the catalogue and looked at the related material. I clicked on medieval history and came upon a book about heraldry titled Heraldry Illustrated by W.B. Abbot, call number CR23.A2. It contained a lot of useful information on how people in the SCA create their identification and family symbols.