Perhaps you're referring to this recent work?
<https://archive.psg.com/181101.imc-communities.pdf>
John
From: NANOG <nanog-bounces@nanog.org> On Behalf Of Arnold Nipper
Sent: Wednesday, March 6, 2019 6:57 PM>
>> A while back I read somewhere that transit providers shouldn't delete
>> communities unless the communities have a specific impact to their
>> network, but my google-fu is failing me and I can't find any sources.
>
> Perhaps you're referring to this recent work?
>
> <https://archive.psg.com/181101.imc-communities.pdf>
>See also
https://2019.apricot.net/assets/files/APKS756/weaponizing-bgp-using-
communities.pdf
And the list goes on...
Route-target extended community anyone? Yup I'm talking about routes being injected to your L3VPN customers'/services' routing-instances(VRFs).
adam