As described in
http://www.cs.uwaterloo.ca/cscf/about/after-hours-support,
there is a mailing list for urgent after hours problem reports.
Nobody is expected to be on this list,
it's strictly voluntary,
for those who might be curious about such things.
It is in no way a commitment to after hours support.
You can subscribe to the list at
https://lists.uwaterloo.ca/mailman/listinfo/cscf-urgent.
Subscriptions require approval,
and the list archives are only available to list members,
to ensure that only CSCF staff see problem reports.
That's done to provide some privacy for those submitting reports.
While many reports could be public, we know that there are
cases where people do want some privacy.
The list is set up to forward responses to the list members, so if you handle a message, make sure an immediate response goes back to the list so that others won't be duplicating your efforts.
Some CSCF staff are willing to make their personal phone numbers available to their colleagues, to be used when/if the cscf-urgent mailing list isn't considered adequate.