  # String types...
  
  class CharField(Field):
      default_error_messages = {
          'blank': _("This field may not be blank."),
          'max_length': _("Ensure this field has no more than {max_length} characters."),
          'min_length': _("Ensure this field has at least {min_length} characters.")
      }
      initial = ''
      coerce_blank_to_null = False
      default_empty_html = ''
  
 
</s> remove         'required': _("This field is required."),
        'null': _("This field may not be null.")
 </s> add         'required': _('This field is required.'),
        'null': _('This field may not be null.') </s> remove         'invalid': _("`{input}` is not a valid boolean.")
 </s> add         'invalid': _('`{input}` is not a valid boolean.') </s> remove     default_detail = _("You do not have permission to perform this action.")
 </s> add     default_detail = _('You do not have permission to perform this action.') </s> remove     message = _("This field must be unique for the \"{date_field}\" date.")
 </s> add     message = _('This field must be unique for the "{date_field}" date.') </s> remove     message = _("This field must be unique for the \"{date_field}\" year.")
 </s> add     message = _('This field must be unique for the "{date_field}" year.')
        'blank': _('This field may not be blank.'),
        'max_length': _('Ensure this field has no more than {max_length} characters.'),
        'min_length': _('Ensure this field has at least {min_length} characters.')
  # String types...
  
  class CharField(Field):
      default_error_messages = {
        'blank': _('This field may not be blank.'),
        'max_length': _('Ensure this field has no more than {max_length} characters.'),
        'min_length': _('Ensure this field has at least {min_length} characters.')
        'blank': _('This field may not be blank.'),
        'max_length': _('Ensure this field has no more than {max_length} characters.'),
        'min_length': _('Ensure this field has at least {min_length} characters.')
        'blank': _('This field may not be blank.'),
        'max_length': _('Ensure this field has no more than {max_length} characters.'),
        'min_length': _('Ensure this field has at least {min_length} characters.')
      }
      initial = ''
      coerce_blank_to_null = False
      default_empty_html = ''
  
keep keep keep keep replace replace replace keep keep keep keep keep
 prefer single quotes in source and double quotes in user visible strings; add some missing full stops to user visible strings 
rest_framework/fields.py