The document discusses three announcements from Microsoft regarding the retirement or deprecation of certain SharePoint and Office 365 features:
1. The Tags & Notes feature in SharePoint Online has been retired and existing tags and notes will be archived in .csv files available for export by administrators.
2. As of March 2017, no new Site Mailboxes can be created in Office 365. Existing Site Mailboxes will continue working until September 2017, after which Office 365 groups should be used instead.
3. Access Services is being retired from Office 365. No new Access apps can be created in SharePoint Online after June 2017, and existing apps will be shut down by April 2018.