Define oblique Mercator and figure out how to compute it

[phma]

The Gauss-Krüger transverse Mercator projection is defined by setting one meridian to map equidistantly to a line and the whole map conformal. That was difficult to implement, but well defined.

One zone in Alaska uses oblique Mercator. So does Switzerland. I don't know how the Alaska projection is defined or whether it's the same as Switzerland. There may be more than one projection called oblique Mercator.

https://download.osgeo.org/proj/swiss.pdf defines the projection used in Switzerland. I can implement that easily (it's two of the three steps for Gauss-Krüger, with the angle not being 90°). But doing that with 90° does not produce Gauss-Krüger; it is not equidistant along the meridian. Nor is the Swiss projection equidistant along its line through Switzerland.

Also, if there are other oblique Mercator projections in use in other parts of the world, I need to know what they are.