Does SST does not support Variable length field in logical ?

["Vengoal Chang" <vengoal@xxxxxxxxxxx>]

Dear folks,
        I want to retrieve some information from system file QADBXTRIGB
on V5R1: I create as following statement LF, but cannot compiled. The
error message is 
CPD7616   : Keyword ignored because of error in list of values.
CPD 7964 : Field on SST keyword must be character or zoned decimal.

     A          R MXTTTR                    PFILE(QADBXTRIGB)     
     A            TFFILE             I      SST(DBXTBTNAME 1 10)  
     A            TFLIB              I      SST(DBXTBTLIB 1 10)   
     A            TTPGM              I      SST(DBXTBPGM 1 10)    
     A            TTLIB              I      SST(DBXTBPGML 1 10)   

And I check those fields in QADBXTRIGB all Variable length field, if I
changed SST to other fixed length field, compiled no problem. Does SST
does not support Variable length field ? Any help will be appreciated.

Best regards,

Vengoal