EXTNAMES system variable
Function Description:
The EXTNAMES system variable is used to set parameters for named object names (such as blocks, linetype, and layers) saved in definition list.
Type : Integer 
Saved in : Drawing
Initial value : 1 
Range : 0,1
System Variable Value:
0 : Names are limited to 31 characters in length. Names can include the letters A to Z, the numerals 0 to 9, and the special characters dollar sign ($), underscore (_), and          hyphen (-). 
1 : Names are limited to 255 characters in length, and can include the letters A to Z, the numerals 0 to 9, spaces, and any special characters not used by Windows system      and GstarCAD for other purposes.