[addaon]

See the other replies — think physical units. An aircraft velocity is a three-vector, but not all three vectors are aircraft velocity. There are probably many different aircraft velocity types, but taking a typical one (NED alignment, mm/s scaling, some particular precision), the type is the set of three vectors that can, for example, be meaningfully added to each other. It makes sense to add two aircraft velocities; it does not make sense to add an aircraft velocity and a pixel color (another three vector), so they are observably different types.

[ramses0]

    Temperature_C != Temperature_F != int8

It's apps hungarian v. systems hungarian all over again. https://en.wikipedia.org/wiki/Hungarian_notation#Systems_Hun...