The following BGP Communities are supported as of now:

0 - no Export
1 - 1x prepend
2 - 2x prepend

Full List of BGP Communities per Location:
Frankfurt:
34927,911x - Meerfarbig
34927,912x - Openfactory
34927,913x - Hurricane Electric
34927,915x - Asympto
34927,916x - GTT
34927,948x - RETN
34927,950x - Deutsche Telekom
34927,947x - Cogent
34927,961x - Telia (export of customer prefixes limit per default)

34927,930x - DE-CIX FRA
34927,931x - KleyReX
34927,932x - LocIX FRA
34927,933x - NL-IX
34927,934x - EVIX
34927,939x - DE-CIX MUC
34927,940x - LocIX DUS
34927,941x - DE-CIX DUS
34927,942x - DE-CIX HAM
34927,950x - DE-CIX MAD
34927,945x - STACIX
34927,963x - FogIXP

Zurich:
34927,913x - Hurricane Electric
34927,956x - Liberty Global
34927,947x - Cogent
34927,965x - Lumen

34927,936x - SwissIX
34927,938x - CHIX-CH
34927,949x - Community-IX

Amsterdam:
34927,912x - Openfactory
34927,913x - Hurricane Electric
34927,956x - Liberty Global
34927,947x - Cogent
34927,957x - WD6
34927,961x - Telia

34927,952x - LSIX
34927,953x - SpeedIX
34927,954x - AMS-IX
34927,955x - FrysIX
34927,960x - NetIX

London:
34927,917x - Zare
34927,913x - Hurricane Electric
34927,915x - Asympto

34927,935x - LINX LON 1
34927,943x - LoNAP

Norway:
34927,918x - TerraHost
34927,913x - Hurricane Electric

34927,937x - FIXO
34927,944x - FSIX

Kansas: - TBC
34927,920x - WSI
34927,913x - Hurricane Electric

34927,946x - KCIX
34927,934x - EVIX
34927,964x - SIX

Fremont:
34927,958x - Mythic Beasts
34927,912x - Openfactory

34927,959x - SFMIX
34927,934x - EVIX
34927,962x - IX Reserved

x=0 - no Export, x=1 - 1x prepend, x=2 - 2x prepend
DE-CIX FRA and FIXO only: x=9 - no Export to direct Peers

Notes: IXPs include direct peers over that IXP.
Some Upstreams / Peerings are v4 or v6 only.

BGP Informal Communities
34927,110 - Transit Frankfurt/EU
34927,130 - Frankfurt IXPs
34927,930 - NL-IX
34927,810 - Transit Switzerland
34927,830 - Switzerland IXPs