 a complementary reference field pair. Otherwise (the current picture is a field), the term reference picture refers either to a reference field or a field of a reference frame. memory_management_control_operation shall not be equal to 1 in a slice header unless the specified reference picture is marked as "used for short-term reference" when the memory_management_control_operation is processed by the decoding process. memory_management_control_operation shall not be equal to 2 in a slice header unless the specified long-term picture number refers to a reference picture that is marked as "used for long-term reference" when the memory_management_control_operation is processed by the decoding process. memory_management_control_operation shall not be equal to 3 in a slice header unless the specified reference picture is marked as "used for short-term reference" when the memory_management_control_operation is processed by the decoding process. memory_management_control_operation shall not be equal to 3 or 6 if the value of the variable MaxLongTermFramel is equal to "no long-term frame indices" when the memory_management_control_operation is processed by the decoding process. Not more than one memory_management_control_operation equal to 4 shall be present in a slice header. Not more than one memory_management_control_operation equal to 5 shall be present in a slice header. Not more than one memory_management_control_operation equal to 6 shall be present in a slice header. memory_management_control_operation shall not be equal to 5 in a slice header unless no memory_management_control_operation in the range of 1 to 3 is present in the same decoded reference picture marking syntax structure. A memory_management_control_operatione equal to 5 shall not follow a memory_management_control_operation equal to 6 in the same slice header. When a memory_management_control_operation equal to 6 is present, any memory_management_control_operation equal to 2, 3, or 4 that follows the memory_management_control_operation, equal to 6 