eudc-attribute-display-method-alist

eudc-attribute-display-method-alist is a variable defined in `eudc-vars.el'.
Its value is

nil

Documentation:
An alist specifying methods to display attribute values.
Each member of the list is of the form (NAME . FUNC) where NAME is a lowercased
string naming a directory attribute (translated according to
`eudc-user-attribute-names-alist' if `eudc-use-raw-directory-names' is
non-nil) and FUNC a function that will be passed the corresponding
attribute values for display.

You can customize this variable.