diff --git a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/model/ContentModelManager.java b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/model/ContentModelManager.java
index f56e63a5d2..705b58ab88 100644
--- a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/model/ContentModelManager.java
+++ b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/model/ContentModelManager.java
@@ -23,6 +23,7 @@
 import org.apache.xerces.xni.grammars.XMLGrammarPool;
 import org.eclipse.lemminx.dom.DOMDocument;
 import org.eclipse.lemminx.dom.DOMElement;
+import org.eclipse.lemminx.extensions.contentmodel.model.ContentModelProvider.Identifier;
 import org.eclipse.lemminx.extensions.contentmodel.participants.diagnostics.LSPXMLGrammarPool;
 import org.eclipse.lemminx.extensions.contentmodel.settings.XMLFileAssociation;
 import org.eclipse.lemminx.extensions.contentmodel.uriresolver.XMLCacheResolverExtension;
@@ -116,10 +117,12 @@ public Collection<CMDocument> findCMDocument(DOMDocument xmlDocument, String nam
 				// The content model provider can collect the system ids
 				// ex for <?xml-model , the model provider which takes care of xml-model returns
 				// the href of xml-model.
-				Collection<String> systemIds = modelProvider.getSystemIds(xmlDocument, namespaceURI);
-				for (String systemId : systemIds) {
+				Collection<Identifier> identifiers = modelProvider.getIdentifiers(xmlDocument, namespaceURI);
+				for (Identifier identifier : identifiers) {
+					String systemId = identifier.getSystemId();
+					String publicId = identifier.getPublicId() != null ? identifier.getPublicId() : namespaceURI;
 					// get the content model document from the current system id
-					CMDocument cmDocument = findCMDocument(xmlDocument.getDocumentURI(), namespaceURI, systemId,
+					CMDocument cmDocument = findCMDocument(xmlDocument.getDocumentURI(), publicId, systemId,
 							modelProvider);
 					if (cmDocument != null) {
 						documents.add(cmDocument);
@@ -151,9 +154,11 @@ public boolean dependsOnGrammar(DOMDocument document, String grammarURI) {
 		}
 		for (ContentModelProvider modelProvider : modelProviders) {
 			if (modelProvider.adaptFor(document, false)) {
-				Collection<String> systemIds = modelProvider.getSystemIds(document, document.getNamespaceURI());
-				for (String systemId : systemIds) {
-					String key = resolverManager.resolve(document.getDocumentURI(), null, systemId);
+				Collection<Identifier> identifiers = modelProvider.getIdentifiers(document, document.getNamespaceURI());
+				for (Identifier identifier : identifiers) {
+					String publicId = identifier.getPublicId();
+					String systemId = identifier.getSystemId();
+					String key = resolverManager.resolve(document.getDocumentURI(), publicId, systemId);
 					if (grammarURI.equals(key)) {
 						return true;
 					}
diff --git a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/model/ContentModelProvider.java b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/model/ContentModelProvider.java
index aedf00aeee..1c241fcc75 100644
--- a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/model/ContentModelProvider.java
+++ b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/model/ContentModelProvider.java
@@ -22,13 +22,34 @@
  */
 public interface ContentModelProvider {
 
+	public class Identifier {
+
+		private final String publicId;
+
+		private final String systemId;
+
+		public Identifier(String publicId, String systemId) {
+			this.publicId = publicId;
+			this.systemId = systemId;
+		}
+
+		public String getPublicId() {
+			return publicId;
+		}
+
+		public String getSystemId() {
+			return systemId;
+		}
+
+	}
+
 	/**
 	 * Returns the content model provider by using standard association
 	 * (xsi:schemaLocation, xsi:noNamespaceSchemaLocation, doctype) an dnull
 	 * otherwise.
 	 * 
 	 * @param document
-	 * @param internal 
+	 * @param internal
 	 * @return the content model provider by using standard association
 	 *         (xsi:schemaLocation, xsi:noNamespaceSchemaLocation, doctype) an dnull
 	 *         otherwise.
@@ -37,7 +58,7 @@ public interface ContentModelProvider {
 
 	boolean adaptFor(String uri);
 
-	Collection<String> getSystemIds(DOMDocument xmlDocument, String namespaceURI);
+	Collection<Identifier> getIdentifiers(DOMDocument xmlDocument, String namespaceURI);
 
 	CMDocument createCMDocument(String key);
 
diff --git a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/dtd/contentmodel/CMDTDContentModelProvider.java b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/dtd/contentmodel/CMDTDContentModelProvider.java
index 2988f68749..1d94fed5e9 100644
--- a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/dtd/contentmodel/CMDTDContentModelProvider.java
+++ b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/dtd/contentmodel/CMDTDContentModelProvider.java
@@ -72,14 +72,15 @@ public boolean adaptFor(String uri) {
 	}
 
 	@Override
-	public Collection<String> getSystemIds(DOMDocument xmlDocument, String namespaceURI) {
+	public Collection<Identifier> getIdentifiers(DOMDocument xmlDocument, String namespaceURI) {
 		/*
 		 * <!DOCTYPE catalog PUBLIC
 		 * "-//OASIS/DTD Entity Resolution XML Catalog V1.0//EN"
 		 * "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
 		 */
 		DOMDocumentType documentType = xmlDocument.getDoctype();
-		return Collections.singleton(documentType.getSystemIdWithoutQuotes());
+		return Collections.singleton(
+				new Identifier(documentType.getPublicIdWithoutQuotes(), documentType.getSystemIdWithoutQuotes()));
 	}
 
 	@Override
diff --git a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xmlmodel/contentmodel/CMXMLModelContentModelProvider.java b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xmlmodel/contentmodel/CMXMLModelContentModelProvider.java
index 72b0ca15da..6fcd412ab0 100644
--- a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xmlmodel/contentmodel/CMXMLModelContentModelProvider.java
+++ b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xmlmodel/contentmodel/CMXMLModelContentModelProvider.java
@@ -47,9 +47,12 @@ public boolean adaptFor(String uri) {
 	}
 
 	@Override
-	public Collection<String> getSystemIds(DOMDocument xmlDocument, String namespaceURI) {
-		return xmlDocument.getXMLModels().stream().map(node -> node.getHref())
-				.filter(href -> !StringUtils.isEmpty(href)).collect(Collectors.toList());
+	public Collection<Identifier> getIdentifiers(DOMDocument xmlDocument, String namespaceURI) {
+		return xmlDocument.getXMLModels().stream() //
+				.map(node -> node.getHref()) //
+				.filter(href -> !StringUtils.isEmpty(href)) //
+				.map(href -> new Identifier(null, href)) //
+				.collect(Collectors.toList());
 	}
 
 	@Override
diff --git a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xsd/contentmodel/CMXSDContentModelProvider.java b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xsd/contentmodel/CMXSDContentModelProvider.java
index 2cc67927bf..e7e44dcab2 100644
--- a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xsd/contentmodel/CMXSDContentModelProvider.java
+++ b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xsd/contentmodel/CMXSDContentModelProvider.java
@@ -55,13 +55,13 @@ public boolean adaptFor(String uri) {
 	}
 
 	@Override
-	public Collection<String> getSystemIds(DOMDocument xmlDocument, String namespaceURI) {
-		Collection<String> systemIds = new ArrayList<>();
+	public Collection<Identifier> getIdentifiers(DOMDocument xmlDocument, String namespaceURI) {
+		Collection<Identifier> identifiers = new ArrayList<>();
 		SchemaLocation schemaLocation = xmlDocument.getSchemaLocation();
 		if (schemaLocation != null) {
 			String location = schemaLocation.getLocationHint(namespaceURI);
 			if (!StringUtils.isEmpty(location)) {
-				systemIds.add(location);
+				identifiers.add(new Identifier(null, location));
 			}
 		} else {
 			NoNamespaceSchemaLocation noNamespaceSchemaLocation = xmlDocument.getNoNamespaceSchemaLocation();
@@ -70,12 +70,12 @@ public Collection<String> getSystemIds(DOMDocument xmlDocument, String namespace
 					// xsi:noNamespaceSchemaLocation doesn't define namespaces
 					String location = noNamespaceSchemaLocation.getLocation();
 					if (!StringUtils.isEmpty(location)) {
-						systemIds.add(location);
+						identifiers.add(new Identifier(null, location));
 					}
 				}
 			}
 		}
-		return systemIds;
+		return identifiers;
 	}
 
 	@Override
@@ -94,7 +94,7 @@ public CMDocument createInternalCMDocument(DOMDocument xmlDocument) {
 		return null;
 	}
 
-	public XSLoaderImpl getLoader() {		
+	public XSLoaderImpl getLoader() {
 		XSLoaderImpl loader = new XSLoaderImpl();
 		loader.setParameter("http://apache.org/xml/properties/internal/entity-resolver", resolverExtensionManager);
 		loader.setParameter(Constants.DOM_ERROR_HANDLER, new DOMErrorHandler() {
diff --git a/org.eclipse.lemminx/src/test/java/org/eclipse/lemminx/extensions/contentmodel/DTDCompletionExtensionsTest.java b/org.eclipse.lemminx/src/test/java/org/eclipse/lemminx/extensions/contentmodel/DTDCompletionExtensionsTest.java
index bbcd39a68b..d2b0f61a45 100644
--- a/org.eclipse.lemminx/src/test/java/org/eclipse/lemminx/extensions/contentmodel/DTDCompletionExtensionsTest.java
+++ b/org.eclipse.lemminx/src/test/java/org/eclipse/lemminx/extensions/contentmodel/DTDCompletionExtensionsTest.java
@@ -11,9 +11,9 @@
 *******************************************************************************/
 package org.eclipse.lemminx.extensions.contentmodel;
 
+import static org.eclipse.lemminx.XMLAssert.CDATA_SNIPPETS;
 import static org.eclipse.lemminx.XMLAssert.COMMENT_SNIPPETS;
 import static org.eclipse.lemminx.XMLAssert.DTDNODE_SNIPPETS;
-import static org.eclipse.lemminx.XMLAssert.CDATA_SNIPPETS;
 import static org.eclipse.lemminx.XMLAssert.PROCESSING_INSTRUCTION_SNIPPETS;
 import static org.eclipse.lemminx.XMLAssert.c;
 import static org.eclipse.lemminx.XMLAssert.te;
@@ -241,12 +241,34 @@ public void attributeCompletionWithDoctypeSubsetWithNoElements() throws BadLocat
 						"xmlns:xsi"));
 	}
 
+	@Test
+	public void completionWithCatalogAndPublic() throws Exception {
+		// This test uses the local DTD with catalog-public.xml by using the PUBLIC ID
+		// -//Sun Microsystems, Inc.//DTD Web Application 2.3//EN
+		// <public publicId="-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
+		// uri="../dtd/web-app_2_3.dtd" />
+		String xml = "<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?> \r\n" + //
+				"<!DOCTYPE web-app\r\n" + //
+				"   PUBLIC \"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN\"\r\n" + //
+				"   \"ABCD.dtd\">\r\n" + //
+				"\r\n" + //
+				"<web-app>|</web-app>";
+		testCompletionFor(xml, true, null, "catalog-public.xml",
+				c("icon", te(5, 9, 5, 9, "<icon>$1</icon>$0"), "icon"), //
+				c("display-name", te(5, 9, 5, 9, "<display-name>$1</display-name>$0"), "display-name"));
+	}
+
 	private void testCompletionFor(String xml, CompletionItem... expectedItems) throws BadLocationException {
 		testCompletionFor(xml, true, null, expectedItems);
 	}
 
 	private void testCompletionFor(String xml, boolean isSnippetsSupported, Integer expectedCount,
 			CompletionItem... expectedItems) throws BadLocationException {
+		testCompletionFor(xml, isSnippetsSupported, expectedCount, "catalog.xml", expectedItems);
+	}
+
+	private void testCompletionFor(String xml, boolean isSnippetsSupported, Integer expectedCount, String catalog,
+			CompletionItem... expectedItems) throws BadLocationException {
 		CompletionCapabilities completionCapabilities = new CompletionCapabilities();
 		CompletionItemCapabilities completionItem = new CompletionItemCapabilities(isSnippetsSupported); // activate
 																											// snippets
@@ -254,7 +276,7 @@ private void testCompletionFor(String xml, boolean isSnippetsSupported, Integer
 
 		SharedSettings sharedSettings = new SharedSettings();
 		sharedSettings.getCompletionSettings().setCapabilities(completionCapabilities);
-		XMLAssert.testCompletionFor(new XMLLanguageService(), xml, "src/test/resources/catalogs/catalog.xml", null,
-				null, expectedCount, sharedSettings, expectedItems);
+		XMLAssert.testCompletionFor(new XMLLanguageService(), xml, "src/test/resources/catalogs/" + catalog, null, null,
+				expectedCount, sharedSettings, expectedItems);
 	}
 }