The Bill of Materials (BOM) in the Asymmetrical Hatted Vertical Dipole Drawing calls out three (3) end caps for the antenna tips in the complete antenna assembly in line item 8.
Please note the DXE-VC-0375 stock number is a bag of twenty (20) end caps. You only need one bag, not three.
The latest version of the drawing makes this more clear with the addition of some vendor information in the parts list. This revision also includes other clarity refinements including a proper ASME font.