O.2 User-user protocol contents

O.4 Information elements

O.3 Information element identifier

L.1 Mapping of NAS procedure to RRC establishment cause(Iu mode only)

K.4 Call control information elements.

K.3 Mobility management information elements.

I.3 Void

I.2 Causes related to invalid messages

K.1 Common information elements.

I.1 Causes related to nature of request