Section: 6.1.3 Information Element instance
Content: Every GTPv2 message and grouped IE within a message in this specification has a column documenting the instance value of each IE. When a GTPv2 message is encoded for use the instance value of each included IE is encoded in the Instance field of the IE for the message scope. See clause 7 and clause 8.2 for details of that encoding. An Information Element in an encoded GTPv2 message or encoded grouped IE is identified by the pair of IE Type and Instance values and described by a specific row in the corresponding tables in clauses of 7 in the present document. If several Information Elements with the same Type and Instance values are included in an encoded GTPv2 message, they represent a list for the corresponding IE name and row identified in the message grammar in clauses of clause 7. If several Information Elements with the same Type and Instance values are included in an encoded grouped IE, they represent a list for the corresponding IE name and row identified in the grouped IE grammar in clauses of clause 7. In tables in this document the instance value for "Private Extension" is marked as VS (Vendor Specific). While an instance value must be encoded by the sender the value can be Vendor and even Private Extension specific. The same IE name might be used in different messages (on the top level or within grouped IEs) in this specification. The instance value and name of an IE is only meaningful within the scope of the message definition . The combination of Type value and Instance value uniquely identifies a specific row in a message description table.