Documented value of type attribute for <f:converNumber> does not match the implementation

The TLD documents "percentage" as an allowable value for the attribute "type" of <f:convertNumber>. This value throws the following exception:
SEVERE: Servlet.service() for servlet jsp threw exception
javax.faces.convert.ConverterException: Cannot get NumberFormat, illegal type percentage
at javax.faces.convert.NumberConverter.getNumberFormat(NumberConverter.java:162)
at javax.faces.convert.NumberConverter.getAsString(NumberConverter.java:117)
at org.apache.myfaces.shared_impl.renderkit.RendererUtils.getStringValue(RendererUtils.java:251)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlTextRendererBase.renderOutput(HtmlTextRendererBase.java:69)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlTextRendererBase.encodeEnd(HtmlTextRendererBase.java:57)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:536)

The implementation is expecting "percent"

Which is correct?