diff --git a/src/java/org/apache/poi/ss/formula/functions/TextFunction.java b/src/java/org/apache/poi/ss/formula/functions/TextFunction.java
index 82082bb9c3..f9562ef857 100644
--- a/src/java/org/apache/poi/ss/formula/functions/TextFunction.java
+++ b/src/java/org/apache/poi/ss/formula/functions/TextFunction.java
@@ -112,18 +112,18 @@ public abstract class TextFunction implements Function {
 	 * Implementation of the PROPER function:
      * Normalizes all words (separated by non-word characters) by
      * making the first letter upper and the rest lower case.
+     * 
+     * This is nearly equivalent to toTitleCase if the Java language had it
 	 */
 	public static final Function PROPER = new SingleArgTextFunc() {
 		protected ValueEval evaluate(String text) {
 			StringBuilder sb = new StringBuilder();
 			boolean shouldMakeUppercase = true;
-			final int length = text.length();
-			for(int i = 0; i < length; ++i) {
-				final char ch = text.charAt(i);
+			for(final char ch : text.toCharArray()) {
 
 				// Note: we are using String.toUpperCase() here on purpose as it handles certain things
 				// better than Character.toUpperCase(), e.g. German "scharfes s" is translated
-				// to "SS" (i.e. two characters), if upercased properly!
+				// to "SS" (i.e. two characters), if uppercased properly!
 				if (shouldMakeUppercase) {
 					sb.append(String.valueOf(ch).toUpperCase(Locale.ROOT));
 				}
diff --git a/src/ooxml/testcases/org/apache/poi/ss/formula/functions/TestProper.java b/src/ooxml/testcases/org/apache/poi/ss/formula/functions/TestProper.java
index cb0be00e34..a9095982c4 100644
--- a/src/ooxml/testcases/org/apache/poi/ss/formula/functions/TestProper.java
+++ b/src/ooxml/testcases/org/apache/poi/ss/formula/functions/TestProper.java
@@ -54,14 +54,25 @@ public final class TestProper extends TestCase {
         cell11 = sheet.createRow(0).createCell(0);
         cell11.setCellType(CellType.FORMULA);
 
-        confirm("PROPER(\"hi there\")", "Hi There");
-        confirm("PROPER(\"what's up\")", "What'S Up");
-        confirm("PROPER(\"I DON'T TH!NK SO!\")", "I Don'T Th!Nk So!");
+        confirm("PROPER(\"hi there\")", "Hi There"); //simple case
+        confirm("PROPER(\"what's up\")", "What'S Up"); //apostrophes are treated as word breaks
+        confirm("PROPER(\"I DON'T TH!NK SO!\")", "I Don'T Th!Nk So!"); //capitalization is ignored, special punctuation is treated as a word break
         confirm("PROPER(\"dr\u00dcb\u00f6'\u00e4 \u00e9lo\u015f|\u00eb\u00e8 \")", "Dr\u00fcb\u00f6'\u00c4 \u00c9lo\u015f|\u00cb\u00e8 ");
-        confirm("PROPER(\"hi123 the123re\")", "Hi123 The123Re");
-        confirm("PROPER(\"-\")", "-");
-        confirm("PROPER(\"!\u00a7$\")", "!\u00a7$");
-        confirm("PROPER(\"/&%\")", "/&%");
+        confirm("PROPER(\"hi123 the123re\")", "Hi123 The123Re"); //numbers are treated as word breaks
+        confirm("PROPER(\"-\")", "-"); //nothing happens with ascii punctuation that is not upper or lower case
+        confirm("PROPER(\"!\u00a7$\")", "!\u00a7$"); //nothing happens with unicode punctuation (section sign) that is not upper or lower case
+        confirm("PROPER(\"/&%\")", "/&%"); //nothing happens with ascii punctuation that is not upper or lower case
+        confirm("PROPER(\"Apache POI\")", "Apache Poi"); //acronyms are not special
+        confirm("PROPER(\"  hello world\")", "  Hello World"); //leading whitespace is ignored
+        
+        final String scharfes = "\u00df$"; //German lowercase eszett, scharfes s, sharp s
+        // CURRENTLY FAILS: result: "Stra"+scharfes+"E"
+        // confirm("PROPER(\"stra"+scharfes+"e\")", "Stra"+scharfes+"e");
+        
+        // CURRENTLY FAILS: result: "SSUnd"+scharfes
+        // LibreOffice 5.0.3.2 behavior: "Sund"+scharfes
+        // Excel 2013 behavior: ???
+        //confirm("PROPER(\""+scharfes+"und"+scharfes+"\")", "SSund"+scharfes);
         
         // also test longer string
         StringBuilder builder = new StringBuilder("A");