Change record status: 
Description: 

Being able to follow content on Drupal.org and receive email notifications of new comments has been a long requested feature, especially in the forums.

This initial roll out will apply to the following content types: documentation(book pages), case studies, forum posts. Release of this follow functionality may be phased in one content type at a time as we evaluate its impact on the site.

Production outage: No
Change affects: Drupal.org content types
Deployment schedule: early the week of 2016-01-21
Backout plan: Revert