Xceed Zip for COM/ActiveX on x86/x64 Documentation
Xceed Zip control reference / Xceed Zip control enumeration types / xcdUnicodeUsagePolicy enumeration
xcdUnicodeUsagePolicy enumeration

xcdUnicodeUsagePolicy
{
xupAlways     = 0,
xupNonASCIIOnly       = 1,
}

This enumeration is used by the UnicodeUsagePolicy property. Explanations on each parameter can be found in that property's help topic.