the use of the "array" flag causes the DHCPv6 encoder to automatically
prefix the variable length strings with a 16-bit length. But it
doesn't hurt to have this information explicit in the dictionaries too
MEMBER Message string
ATTRIBUTE Rapid-Commit 14 bool
-ATTRIBUTE User-Class 15 octets array
+ATTRIBUTE User-Class 15 octets length=uint16,array
ATTRIBUTE Vendor-Class 16 struct
MEMBER PEN uint32
-MEMBER Data octets array
+MEMBER Data octets length=uint16,array
ATTRIBUTE Vendor-Opts 17 vsa
ATTRIBUTE Interface-ID 18 octets