Referencing the PIC16/17 Microcontroller Data Book in the PIC16C84 section
subsection 8.2.2 "The PIC16C84 oscillator design requires the use of a parallel
cut crystal. Use of a series cut crystal may give a frequency out of
the crystal manufactures specifications"

Also referencing the PIC16C84 section table 8-2 crystals tested:
ECS ECS-40-S-4

Also referencing the Digikey July-August 1996 catalog page 179
Frequency               4.000 Mhz
Max Series Load Cap.    Series
ECS Part No             ECS-40-S-4


Could some one explain this to me? Do I have to look for a Load Cap.
rating of series to get a parallel cut crystal and not a series?

Please, could you make it crystal clear? Sorry couldn't resist.  ;-}