Update the readme as well

readme.md

@@ -84,3 +84,15 @@ The application will report text strings containing only one expression with a
 For example `"<<$variable>>"` can be written directly: `$variable>`. This test
 will not report this usage when an integer converted into a string this way.
 
+### Duplicated test
+
+In a single if branch, check if the same is repeated more than one once. In
+this case, only the first case is executed and the other test is ignored.
+
+A warining will be raised here:
+
+    if $value = '1': 
+        ! Do something
+    elseif $value = '1':
+        ! Do something else
+    end