somebody please tell me embossed black and re-black what does it mean .
and this one
AnMay might be correct, but
that looks like the PN that is to be printed/embossed on the assembly. (Look at the PN of the second drawing)
That looks like two different types of black with their colour code (86 resp. 91) according to company standard.
For the exact look of this two types of colour you will have to ask the manufacturer.
You can compare this to RAL.
E. g. RAL 9004, RAL 9005, RAL 9011, RAL 9017 are all black but different kinds of black.