what does this icon in corner of odyssey settlements mean?

[Norlav]

when browsing list of odyssey settlements in system map, some have this icon in upper right and some don't. I couldn't figure out a pattern yet. What does the icon mean?

https://imgur.com/a/vDMYM5t

Source: https://imgur.com/a/vDMYM5t

 

[Rat Catcher]

Settlement on an Atmo body, I think.

 

[metatheurgist]