diff --git a/docs/architecture_components.md b/docs/architecture_components.md
index 924c0044..3e5764dc 100644
--- a/docs/architecture_components.md
+++ b/docs/architecture_components.md
@@ -23,6 +23,8 @@ To suggest a new domain, start a discussion in [the architecture repository](htt
 
 These integrations interact with external devices & services and make them available in Home Assistant via integrations that define IoT domains like `light`.  An example of such an integration is Philips Hue. Philips Hue lights are made available as light entities in Home Assistant.
 
+Integrations which interact with external devices & services are generally not allowed to consume the state of entities from other integrations, with the exception of entities from other integrations which have a location, e.g. the state of zone and device_tracker entities.
+
 For more information, see [entity architecture](architecture/devices-and-services.md).
 
 ## Represent virtual/computed data points