Paul, You never stated why the disparity in sizes. It is because those sizes refer to a bore diameter, because of flow volumnes.
Re the JIC fittings, where I have worked we have refered to them (rightly or wrongly) as "bar" 8 (1/2"), or bar 12 etc. and the one you left out Bar 16, (1 inch) (obviously in 16ths, hence Bar 20)
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Perry, how ever it's designated in your book, BSP T or Tr, and BSP P or BSP Pl, it still stands for taper or parrellel.