[appfuse-user] duplicate errors.email in errors.properties and ApplicationResource.properties?

[maker su]

Hi,
The errors.email(for example) is both exist in errors.properties and
ApplicationResource.properties.
And signup.html use errors.properties.
My question is why there is duplicate errors.email declare in
ApplicationResource.properties?
When will use errors.email in ApplicationResource.properties?
Please hint.
Thanks,
Maker Su