DXF Group Codes

The following table gives the group code or group code range accompanied
by an explanation of the group code value. In the table, "fixed" indicates
that this group code always has the same purpose. The purpose of group codes that aren't fixed can vary depending on the context.

Entity group codes by number :

Group code	Description

-5		APP: persistent reactor chain
-4		APP: conditional operator (used only with ssget)
-3		APP: extended data (XDATA) sentinel (fixed)
-2		APP: entity name reference (fixed)
-1		APP: entity name. This changes each time a drawing is opened.
		It is never saved. (fixed)
0		Text string indicating the entity type (fixed)
1		Primary text value for an entity
2		Name (attribute tag, block name, and so on)
3-4		Other textual or name values
5		Entity handle. Text string of up to 16 hexadecimal digits (fixed)
6		Linetype name (fixed)
7		Text style name (fixed)
8		Layer name (fixed)
9		DXF: variable name identifier (used only in HEADER section of the DXF file).
10		Primary point. This is the start point of a line or text entity, center of
		a circle, and so on. 
		DXF: X value of the primary point (followed by Y and Z value codes 20 and 30)
		APP: 3D point (list of three reals)
11-18		Other points. 
		DXF: X value of other points (followed by Y value codes 21-28 and Z value 
		codes 31-38)
		APP: 3D point (list of three reals)
20, 30		DXF: Y and Z values of the primary point 
21-28, 31-37	DXF: Y and Z values of other points 
38		DXF: entity's elevation if nonzero. Exists only in output from versions 
		prior to AutoCAD Release 11.
39		Entity's thickness if nonzero (fixed)
40-48		Floating-point values (text height, scale factors, and so on)
48		Linetype scale. Floating-point scalar value. Default value is defined for 
		all entity types.
49		Repeated floating-point value. Multiple 49 groups may appear in one entity 
		for variable-length tables (such as the dash lengths in the LTYPE table). 
		A 7x group always appears before the first 49 group to specify the table 
		length.
50-58		Angles (output in degrees to DXF files and radians through AutoLISP and 
		ARX applications). 
60		Entity visibility. Integer value. Absence or 0 indicates visibility;
		1 indicates invisibility. 
62		Color number (fixed)
66		"Entities follow" flag (fixed)
67		Space--that is, model or paper space (fixed)
68		APP: identifies whether viewport is on but fully off screen; is not active 
		or is off.
69		APP: viewport identification number.
70-78		Integer values, such as repeat counts, flag bits, or modes
90-99		32-bit integer values
100		Subclass data marker (with derived class name as a string). Required for 
		all objects and entity classes that are derived from another concrete class 
		to segregate data defined by different classes in the inheritance chain for 
		the same object.
		This is in addition to the requirement for DXF names for each distinct 
		concrete class derived from ARX (see "Subclass Markers").
102		Control string, followed by "{" or "}". Similar to the 
		xdata 1002 group code, except that when the string begins with "{", it 
		can be followed by an arbitrary string whose interpretation is up to the 
		application.
		The only other allowable control string is "}" as a group terminator. 
		As noted before, AutoCAD does not interpret these strings except during 
		drawing audit operations; they are for application use.
105		DIMVAR symbol table entry object handle
210		Extrusion direction (fixed). 
		DXF: X value of extrusion direction
		APP: 3D extrusion direction vector
220, 230		DXF: Y and Z values of the extrusion direction
280-289		8-bit integer values
300-309		Arbitrary text strings
310-319		Arbitrary binary chunks with same representation and limits as 1004 group 
		codes: hexadecimal strings of up to 254 characters represent data chunks 
		of up to 127 bytes.
320-329		Arbitrary object handles. Handle values that are taken "as is." They are 
		not translated during INSERT and XREF operations. 
330-339		Soft-pointer handle. Arbitrary soft pointers to other objects within same 
		DXF file or drawing. Translated during INSERT and XREF operations. 
340-349		Hard-pointer handle. Arbitrary hard pointers to other objects within same 
		DXF file or drawing. Translated during INSERT and XREF operations. 
350-359		Soft-owner handle. Arbitrary soft ownership links to other objects within 
		same DXF file or drawing. Translated during INSERT and XREF operations. 
360-369		Hard-owner handle. Arbitrary hard ownership links to other objects within 
		same DXF file or drawing. Translated during INSERT and XREF operations. 
999		DXF: The 999 group code indicates that the line following it is a comment 
		string. DXFOUT does not include such groups in a DXF output file, but 
		DXFIN honors them and ignores the comments. You can use the 999 group to 
		include comments in a DXF file that you've edited.
1000		ASCII string (up to 255 bytes long) in extended data.
1001		Registered application name (ASCII string up to 31 bytes long) for 
		extended data.
1002		Extended data control string ("{"or "}").
1003 		Extended data layer name.
1004		Chunk of bytes (up to 127 bytes long) in extended data.
1005		Entity handle in extended data. Text string of up to 16 hexadecimal digits 
1010		A point in extended data 
		DXF: X value (followed by 1020 and 1030 groups)
		APP: 3D point
1020, 1030	DXF: Y and Z values of a point
1011		A 3D world space position in extended data 
		DXF: X value (followed by 1021 and 1031 groups)
		APP: 3D point
1021, 1031	DXF: Y and Z values of a World space position
1012		A 3D world space displacement in extended data
		DXF: X value (followed by 1022 and 1032 groups)
		APP: 3D vector
1022, 1032	DXF: Y and Z values of a World space displacement
1013		A 3D world space direction in extended data. 
		DXF: X value (followed by 1022 and 1032 groups)
		APP: 3D vector
1023, 1033	DXF: Y and Z values of a World space direction
1040		Extended data floating-point value.
1041		Extended data distance value.
1042		Extended data scale factor.
1070		Extended data 16-bit signed integer.
1071		Extended data 32-bit signed long.