diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 735343fc857a7b3a6803a59e1ae3f33a7b5090e2..d4996cf46eb6ac0b2227a28ff26c734568b86f99 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1179,7 +1179,18 @@ static int format_decode(const char *fmt, struct printf_spec *spec)
  * %ps output the name of a text symbol without offset
  * %pF output the name of a function pointer with its offset
  * %pf output the name of a function pointer without its offset
- * %pR output the address range in a struct resource
+ * %pR output the address range in a struct resource with decoded flags
+ * %pr output the address range in a struct resource with raw flags
+ * %pM output a 6-byte MAC address with colons
+ * %pm output a 6-byte MAC address without colons
+ * %pI4 print an IPv4 address without leading zeros
+ * %pi4 print an IPv4 address with leading zeros
+ * %pI6 print an IPv6 address with colons
+ * %pi6 print an IPv6 address without colons
+ * %pI6c print an IPv6 address as specified by
+ *   http://www.ietf.org/id/draft-kawamura-ipv6-text-representation-03.txt
+ * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
+ *   case.
  * %n is ignored
  *
  * The return value is the number of characters which would