The following group codes apply to polyline entities.
Polyline group codes
Group code
Description
100
Subclass marker (AcDb2dPolyline or AcDb3dPolyline)
66
Obsolete; formerly an “entities follow flag” (optional; ignore if present)
10
DXF: always 0
APP: a “dummy” point; the X and Y values are always 0, and the Z value is the polyline's elevation (in OCS when 2D, WCS when 3D)
20
DXF: always 0
30
DXF: polyline's elevation (in OCS when 2D; WCS when 3D)
39
Thickness (optional; default = 0)
70
Polyline flag (bit-coded; default = 0):
1 = This is a closed polyline (or a polygon mesh closed in the M direction)
2 = Curve-fit vertices have been added
4 = Spline-fit vertices have been added
8 = This is a 3D polyline
16 = This is a 3D polygon mesh
32 = The polygon mesh is closed in the N direction
64 = The polyline is a polyface mesh
128 = The linetype pattern is generated continuously around the vertices of this polyline
40
Default start width (optional; default = 0)
41
Default end width (optional; default = 0)
71
Polygon mesh M vertex count (optional; default = 0)
72
Polygon mesh N vertex count (optional; default = 0)
73
Smooth surface M density (optional; default = 0)
74
Smooth surface N density (optional; default = 0)
75
Curves and smooth surface type (optional; default = 0); integer codes, not bit-coded:
0 = No smooth surface fitted
5 = Quadratic B-spline surface
6 = Cubic B-spline surface
8 = Bezier surface
210
Extrusion direction (optional; default = 0, 0, 1)
DXF: X value; APP: 3D vector
220, 230
DXF: Y and Z values of extrusion direction (optional)
Xdata with the "AUTOCAD_POSTSCRIPT_FIGURE" application ID may follow a polyline entity. This contains information related to PostScript images and PostScript fill information.