Upstream: https://we.phorge.it/T15838

User story: As a user looking for direction on how to search by ID, I would like a message with more guidance, so that I can find my way to the proper format on my own.

You can search for specific task IDs by leveraging a hidden "IDs" field, revealed when a search URL takes the following format: https://phabricator.wikimedia.org/maniphest/?ids=1,2,3,4#R

This is a very useful feature! (Useful enough that it might warrant being visible by default, but that's a separate issue).

The field will also appear if you type in, say, https://phabricator.wikimedia.org/maniphest/?ids=T123. However, the addition of a non-numerical value ("T", as most tasks are prefixed and might be intuited), while allowed in the field once it is revealed, will throw an error when clicking "Search":

I have updated documentation to mitigate the issue, but I still think it would be inclusive and friendly to change this error. :)