Rebar marking type-4(with under line). 
 
  File name : B4.LSP

     Exmaple 
    Select objects: {p1}~{p2} 5 found                   [Select dot rebars]
    Select objects:                            [Finish selecting]
    Pick base line first point: {p3}            [Pick Start point of underline]
      Pick base line second point: {p4}               [³¡Á¡]
    Pick base line: {p5}                                [Pick side point of under line]
    Enter Marking: b4                          [Enter Name of rebar]
    Enter Rebar Dia: d25                               [Enter diameter of rebar]