Facebook > Campaign Performance > By Device and Platform

Device > "Other"

Data rows containing a device named, "other" represent a collection of devices that either do not have a device name or is a device name that is unknown to Facebook.

This data row should represent a tiny fraction of all of the data shown within the table. 

Platform > "Unknown"

Undisclosed publishers on a Delivery Report refer to a small number of publishers who have an agreement with Facebook to remain undisclosed. You can see the number of impressions, but not the name of the publisher.

These undisclosed publishers are still subject to the same checks as every other publisher and have been screened for objectionable content.

Platform > "Audience_Network"

Facebook Audience Network is an off-Facebook, in-app advertising network for mobile apps. Majority Strategies can serve up their ads to our audiences who are using mobile sites and apps other than Facebook, extending our reach beyond the platform while still getting to use Facebook’s exceptionally powerful ad system.