XCLIPFRAME system variable
Function Description:
The XCLIPFRAME system variable is used to determine whether to display or plot the xref clipping boundaries in current drawing.
 Type : Integer 
Saved in : Drawing 
Initial value : 2 
Range : 0,1,2
System Variable Value:
0 : the frame is invisible and could not plot it
     The frame could temporarily redisplay when previewing selection set or duration of selecting objects 
1 : display and plot xref frame for clipping
2 : display but not plot xref frame for clipping