From my post on the dev@ list:
Currently, EnumChoiceRenderer escapes the value via the postprocess method.
It seems to be redundant with the fact that DropDownChoice already
escapes the value by default (in AbstractChoice).
Typically, in a default setup, if you use EnumChoiceRenderer and
DropDownChoice together, your value is escaped twice which leads to a
double escaped value.
Should I open a JIRA so that we remove the escaping of EnumChoiceRenderer?