Termination-Cause-SLg  AVP ( 2548 )

The valid values are defined in the referenced specification. "MT_LR_Restart" cause code shall be used to trigger the GMLC to restart the location procedure, either because the sending node knows that the terminal has moved under coverage of another SGSN or MME, or because the subscriber has been deregistered due to a Cancel Location received from HSS. Any unrecognized value of Termination-Cause shall be treated the same as value 1 ("Error Undefined").

Reference: 3GPP TS 29.172-f00   View