void (@NotNull PsiReferenceRegistrar registrar) { HtmlReferenceProvider provider = new HtmlReferenceProvider(); String[] htmlAttrs = HtmlReferenceProvider.getAttributeValues(); ElementFilter htmlFilter = HtmlReferenceProvider.getFilter(); XmlUtil.registerXmlAttributeValueReferenceProvider(registrar, htmlAttrs, htmlFilter, false, provider); XmlUtil.registerXmlAttributeValueReferenceProvider(registrar, new String[] {"content"}, new ScopeFilter( new ParentElementFilter( new AndFilter(XmlTagFilter.INSTANCE, new XmlTextFilter("meta")), 2 ) ), true, new HtmlHttpEquivEncodingReferenceProvider()); }