Back in Bugzilla there was a "shell" tag. It was created in old times when there were only a handful of people running the infrastructure and having server shell access. So then it made sense to tag bugs that needed a person with shell access.
Nowadays though, even before the switch to Phabricator, it didn't make that much sense anymore, for several reasons.
We have an operations team, a platform engineering team, deployers, other groups like researchers and analysists, and they all have some kind of shell or another, but they are different. So the word 'shell' in itself doesn't say much anymore. If anything it meant actually 'root' but sometimes it meant 'deploy mw config' and sometimes anything that couldn't be solved on a wiki.
Also nowadays we use configuration management like puppet and the aim would be to get rid of manual "shell" things as much as possible, so often these tasks used to be shell tasks in the past, but now they should just be puppet patches. And that means anyone could create those patches and so on.
The point is, we imported that tag into phab, but i don't think it's helpful.
is a mix of things, some need Operations, some just need patches by anyone, some need Platform Eng and so on
I suggest to remove that tag and replace it with more relevant ones, like Operations, platformeng and others.