SDE:server,instanz,db,user,pw,table table 
ogrinfo -al -so SDE:server,instanz,db,user,pw,table table

LAYER
  ...
  CONNECTIONTYPE PLUGIN
  CONNECTION "hostname,port:xxx,database,username,password"
  PLUGIN "C:/mapserver/bin/msplugin_sde_93.dll"
  DATA "layername,geometrycolumn,SDE.DEFAULT"
  ...
END # layer