TAG 

     TAG is used to identify a group of GFA FZLVL elements. FZLVLs 
     with the same tags can be smeared together. 

     The value of TAG can be 1W, 2W, ..., 9W, 1C, 2C, ..., 9C, 1E, 
     2E, ..., 9E. 

     The default value is 1W.