During the Icetide of 468 LV, several series of related cortex entries were made available. They are categorized into 4 different sections:
The following show the methods to obtain these entries.
Found Archive—One Last Chance
There are 12 entries in total. This collection serves as the midquel and in a way both the prequel and sequel (depending upon the entry) for the short story Bountiful Hunt.
To unlock each these cortex entries in the series, 5 
collectible notes must be gathered from active sentinel camps throughout Northern Bastion. So, a total of 60 notes must be collected to get all 14 Outlaw Correspondence: Icetide Cortex entries.
Promising
There are 11 entries in total. This collection acts as the prequel to the short story Troublemaker
To obtain one entry, 5 collectible notes must be collected in Freeplay. To collect all 11 entries, a total of 55 notes must be collected in active scar camps.
Outlaw Correspondence: Icetide
There are 14 entries in total.
To unlock each these cortex entries in the series, 5 collectible notes must be gathered from active outlaw camps throughout Northern Bastion. So, a total of 70 notes must be collected to get all 14 Outlaw Correspondence: Icetide Cortex entries.
Icetide Wishes
There are 10 hidden Icetide Wishes in total.
Wreaths are spread all across Northern Bastion and marked as collectible notes. There are 10 wreaths spread across different locations in each of the 10 sub-regions of Northern Bastion. When 10 wreaths are activated in a particular sub region, the hidden Icetide wishes show up. In total, there are 100 wreaths to activate and 10 secret wishes to collect from 10 sentinels.
Note: These entries could only be collected during the Season of Icetide of 2019 and helped complete the Endurance Challenge Collection: Left Out In The Cold. If the challenge is not active, then the wishes cannot be activated.
Tips and Tricks
- It is possible to collect all entries in a few Freeplay sessions.
- An easy way to collect them is to keep flying between a few camps as these collectible notes will reset approximately every 5 minutes.
- Wreaths may be bugged due to them being collectibles and also because once they are activated they cannot be interacted with again. So, even if all the wreaths are activated, some may not show up. In this case, collecting them through a second pilot is advised.