CoefficientField  symbol used to define the ground field in many routines
See also

carpet  ideal of a K3 carpet

correspondenceScroll  Union of planes joining points of rational normal curves according to a given correspondence

hankelMatrix  matrix with constant antidiagonal entries

productOfProjectiveSpaces  Constructs the multigraded ring of a product of copies of P^1 (pp is a synonym)
Functions with optional argument named CoefficientField :

carpet(...,CoefficientField=>...)  see carpet  ideal of a K3 carpet

productOfProjectiveSpaces(...,CoefficientField=>...)  see productOfProjectiveSpaces  Constructs the multigraded ring of a product of copies of P^1 (pp is a synonym)