gsiftp protocol documentation

[rmathar]

The URL vdt.cs.wisc.edu in section 10.2.4 of the cfitsio.pdf of Aug 2024 or March 2025
is broken.
One might replace it by https://github.com/globus/globus-toolkit,
but note that the package should be considered obsolete:
The most recent changes are 6 years old.
I also think that www.globus.org mentioned in Section 10.2.4 is now resold to a different
organization, and it is not clear whether the gsiftp protocol
is still documented anywhere.