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But keep the:

Host narval
  Hostname localhost

you probably already have.

With that one will get ask once every 19 years on each machine (narval1, narval2, ...) to authenticate when submitting a job with soumet.

Automated workflows

This refers to connections to clusters of The Alliance for which you are not around to authenticate yourself. For example, automated nightly data transfers or job checks with crontabs.
Have a look at the official wiki page of The Alliance:

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