creo4 config.pro option documentation for: MAT_ASSIGN_APPEARANCE 
mat_assign_appearance
Category: Colors
Description: Control whether default appearance in material definition is automatically assigned to a part.
Values: yes, no
Default Values: yes
v id="ww3_3_8_5_3_8_3" class="Body">This option applies to gouge checking in Milling. Set this option to yes
if you want the system to automatically include all reference part surfaces as Check Surfaces for Profiling and Pocketing NC sequences.