# Preferences

## User Preferences

`datareporting.healthreport.uploadEnabled`

This determines whether the Glean SDK is enabled.
It can be controlled by users via `about:preferences#privacy`.
If this is set to false from true, we send a
["deletion-request" ping](https://mozilla.github.io/glean/book/user/pings/deletion_request.html)
and no data collections will be persisted or reported from that point.

## Test-only Preferences

`telemetry.fog.test.localhost_port`

If set to a value `port` which is greater than 0, pings will be sent to
`http://localhost:port` instead of `https://incoming.telemetry.mozilla.org`.
If set to a value which is less than 0, FOG will not squelch all sent pings,
telling the Glean SDK that the ping was sent successfully.
Defaults to 0.