Data Review
-----------
**Everything that lands in mozilla-central that adds or expands data
collection must go through the data review process.**
This will require assessing the sensitivity of the data that is being
collected, and going through the `sensitive data collection
process <
https://wiki.mozilla.org/Data_Collection#Step_3:_Sensitive_Data_Collection_Review_Process>`__
if necessary. All data collection is subject to our `overall data
collection policy <
https://wiki.mozilla.org/Data_Collection>`__.
Documentation for the data collection request process and the
expectations we have for people following it `lives on the
wiki <
https://wiki.mozilla.org/Data_Collection#Requesting_Data_Collection>`__.
This document describes the technical implementation in Phabricator
using tags.
1. Any change that touches metrics will be automatically flagged with a
``needs-data-classification`` tag by Phabricator, using `this herald
rule <
https://phabricator.services.mozilla.com/H436>`__. If a change
adds/updates data collection in a way that doesn’t automatically
trigger this rule, this tag should be added manually (and if
appropriate, please file a bug to update the herald rule so it
happens automatically next time).
2. After assessing data sensitivity, the tag can be replaced with either
``data-classification-low`` or ``data-classification-high`` depending
on that sensitivity.
3. Adding ``data-classification-high`` will auto-add the ``#data-stewards``
reviewer group as a blocking reviewer for the change and initiate the
`sensitive data review process <
https://wiki.mozilla.org/Data_Collection#Step_3:_Sensitive_Data_Collection_Review_Process>`__.
4. For patches making mechanical changes that happen to trigger the
herald rule linked above, but that do not actually add or update any
data collection, the ``data-classification-unnecessary`` tag can be used.
Patches with the ``needs-data-classification`` tag will not be landable in
Lando. The process linked above must be followed in order to land the
change.
