creo4 config.pro option documentation for: CAN_SNAP_TO_MISSING_REF 
can_snap_to_missing_ref
Category: Assembly
Description: Controls whether to enable snapping to missing references while dragging components for placement. Yes - Snapping is enabled while dragging. No - Snapping is disabled while dragging.
Values: yes, no
Default Values: yes
ines the default color for welds. The three decimal values specify, in this order, the percentages of red, green, and blue in the resulting color. For example, 0 0 49 specifies a medium blue color. The decimal values range from 0 through 100.