Can you confirm what it is you are trying to do?
Below we see a set of flag_reasons:
These all relate to the various flag options:
The flag_reasons.<some_reason> strings make up part of the message that is sent to a user to let them know that their post was flagged/removed.
The flag_reasons.responder.<some_reason> makes up part of the message that is sent to users who responded to a flagged post that was removed. This feature was introduced in FEATURE: Notify responders of post removal by janzenisaac · Pull Request #15049 · discourse/discourse · GitHub and is default disabled. It can be enabled via the notify_users_after_responses_deleted_on_flagged_post site setting.
There are also a couple of flag_reason (no s) strings:
These are used in the reviewable descriptions of automatically flagged posts. The text is only ever shown to admins and moderators:
