_nomap
The underscore nomap suffix in SSID indicates your desire to opt-out of Wi-Fi positioning systems and, in some cases, mass surveillance. This used to be a not so great blog-post and has since became a hopefully better note to whoever it may concern
_nomap
in the end of your SSID will exclude your network from Google, Apple,
WiGLE etc.
Wikipedia has a more complete list of supporting services.
Microsoft has a separate location services opt-out which uses MAC addresses instead.
Hidden SSID won’t work for opt-out in some of those services. Refer to n/hiddenssid.
Automaattinen sisällysluettelo / Automatically generated Table of Contents
Why?
Privacy. WiGLE.net may point your home directly just by entering the SSID and who knows how many similar services there are. While I have been thinking of this since 2015, there is at least one case where this has been used in 2018:
In the second quarter of 2024, researchers found that Apple allows tracking Wi-Fi networks that hadn’t opted out, including Starlink terminals in Ukraine and Gaza.
_optout
Legacy from 2015-2016. Used to be part of Microsoft WiFi Sense that shared WiFi networks and passwords to all contacts.