I think those are two different things, but I have tried for quite some time to remove the "Viewport" text reference from this collector, but still the only way I am aware of, but I use it with a Filter.
internal static IList<ElementType> ViewportTypes(Document doc)
{
FilterRule rule = ParameterFilterRuleFactory.CreateEqualsRule(new ElementId((long)BuiltInParameter.SYMBOL_FAMILY_NAME_PARAM), "Viewport");
ElementParameterFilter filter = new ElementParameterFilter(rule);
FilteredElementCollector fec = new FilteredElementCollector(doc).OfClass(typeof(ElementType)).WherePasses(filter);
return fec.Cast<ElementType>().ToList();
}