[Proj] Confused about geos projection documentation

[Frank Willett]

Hi All,

In the new documentation for the geos projection at:
http://trac.osgeo.org/proj/wiki/proj%3Dgeos

I'm confused because it contains the following two statements:

sweep: the sweep angle axis of the viewing instrument. Can be x or y
(x is the default). (new in 4.8.0)

and

The sweep argument is used to tell proj.4 which on which axis the
outer-gimbal is rotating. The possible values are x or y, y being the
default.

Which of these statements is correct?

Thanks for your input :-)

Frank Willett