[Tagging] Difference between barrier=embankment and man_made=embankment?

[Joseph Eisenberg]

The tag barrier=embankment was not part of the original barriers
proposal and does not have a wiki page, but it is used 4750 times:
https://taginfo.openstreetmap.org/tags/barrier=embankment

However, man_made=embankment is well-documented and used over 80,000
times: https://wiki.openstreetmap.org/wiki/Tag:man_made=embankment

There is also a tag "embankment=yes" that can be applied to linear
features like roads, similar to "cutting=yes".

And there is barrier=retaining_wall which is documented:
https://wiki.openstreetmap.org/wiki/Tag:barrier=retaining_wall

How is this tag being used? Are there any situations where
barrier=embankment is better or at least clearly different than
man_made=embankment?

(Note that this tag is currently rendered by the Openstreetmap-Carto
style like a retaining wall or fence, while man_made=embankment has a
specific rendering, but this could change)