What is Arctic Control Area (ACA)? I saw that in Jeppesen airway manual but I didn't find a definition for it. What is that?

How to establish it? Who establishes it and for what reason?
from 
http://code7700.com/high_latitude.htm

Apparently defined by Transport Canada:

https://www.tc.gc.ca/media/documents/ca-publications/AIM-2018-1-E-ACCESS.pdf

page 192