VISRETAIN
Determines how visibility, color, linetype, lineweight, and print style settings of the layers for an external reference are viewed. Use one of the following values:
0 = Layers that apply to the external reference are viewed according to the layer settings saved in the external reference. Changed layer settings affect the current session only.
1 = Layers that apply to the external reference are viewed according to the layer settings, if changed, in the current drawing. Changed layer settings are saved with the current drawing.
Type: Integer
Saved: In the drawing file
Range: 0, 1
Default: 1