Originally Posted by
onehundred80
The clocks are to indicate the date and sometimes the time the part was molded. The HC/PP is the material, a common material is PC/ABS which is a combination of Poly Carbonate and Acrylonitrile Butadiene Styrene, you can see why it is normally called ABS.
PP is Polypropylene, HC I do not know (typo?)
I think it is "High Crystalline" Polypropylene. Typically is listed w/o the "/" between (HCPP).