Cylindrical projection with one standard parallel v0 or two standard parallels v1 and v2.
In case of normal position of the projection axis we have always:
v0 = 0 resp. v2 = - v1 .
Conic projection with one standard parallel v0 or two standard parallels v1 and v2.
In case of normal position of the projection axis we always have:
0 < |v0| < / 2 resp. v2 ≠ - v1 .