diff --git a/XML/include/Poco/DOM/DOMParser.h b/XML/include/Poco/DOM/DOMParser.h
index 1a60c2438..de24fea3f 100644
--- a/XML/include/Poco/DOM/DOMParser.h
+++ b/XML/include/Poco/DOM/DOMParser.h
@@ -45,7 +45,11 @@ public:
 		/// If a NamePool is given, it becomes the Document's NamePool.
 		
 	explicit DOMParser(unsigned long namePoolSize);
-		/// Creates a new DOMParser, using the given name pool size.
+		/// Creates a new DOMParser, using the given NamePool size.
+		///
+		/// The given namePoolSize should be a suitable prime number, 
+		/// e.g. 251, 509, 1021 or 4093, depending on the expected
+		/// size of the document.
 
 	~DOMParser();
 		/// Destroys the DOMParser.
diff --git a/XML/include/Poco/XML/NamePool.h b/XML/include/Poco/XML/NamePool.h
index 7ff81ca5d..426208c4a 100644
--- a/XML/include/Poco/XML/NamePool.h
+++ b/XML/include/Poco/XML/NamePool.h
@@ -44,6 +44,9 @@ class XML_API NamePool
 public:
 	NamePool(unsigned long size = POCO_XML_NAMEPOOL_DEFAULT_SIZE);
 		/// Creates a name pool with room for up to size strings.
+		///
+		/// The given size should be a suitable prime number, 
+		/// e.g. 251, 509, 1021 or 4093.
 	
 	const Name& insert(const XMLString& qname, const XMLString& namespaceURI, const XMLString& localName);	
 		/// Returns a const reference to an Name for the given names.