Index: /trunk/include/iprt/string.h
===================================================================
--- /trunk/include/iprt/string.h	(revision 74707)
+++ /trunk/include/iprt/string.h	(revision 74708)
@@ -1530,4 +1530,8 @@
  *                            it in quotes with proper JSON escaping.
  *
+ *      - \%RMpa            - Takes a string pointer (const char *) and outputs
+ *                            it percent-encoded (RFC-3986).  All reserved characters
+ *                            are encoded.
+ *
  *      - \%RMpf            - Takes a string pointer (const char *) and outputs
  *                            it percent-encoded (RFC-3986), form style.  This
Index: /trunk/src/VBox/Runtime/common/string/strformatrt.cpp
===================================================================
--- /trunk/src/VBox/Runtime/common/string/strformatrt.cpp	(revision 74707)
+++ /trunk/src/VBox/Runtime/common/string/strformatrt.cpp	(revision 74708)
@@ -1459,5 +1459,5 @@
 
                     *ppszFormat += 2;
-                    AssertMsgBreak(chVariant == 'p' || chVariant == 'q' || chVariant == 'f',
+                    AssertMsgBreak(chVariant == 'a' || chVariant == 'p' || chVariant == 'q' || chVariant == 'f',
                                    ("Invalid IPRT format type '%.10s'!\n", pszFormatOrg));