diff --git a/central_backend/src/devices/device.rs b/central_backend/src/devices/device.rs
index 400ca23..c577bdc 100644
--- a/central_backend/src/devices/device.rs
+++ b/central_backend/src/devices/device.rs
@@ -1,11 +1,20 @@
+//! # Devices entities definition
+
+/// Device information provided directly by the device during syncrhonisation.
+///
+/// It should not be editable fro the Web UI
 #[derive(Clone, Debug, serde::Serialize, serde::Deserialize)]
 pub struct DeviceInfo {
+    /// Device reference
     reference: String,
+    /// Device firmware / software version
     version: semver::Version,
+    /// Maximum number of relay that the device can support
     max_relays: usize,
 }
 
 impl DeviceInfo {
+    /// Identify errors in device information definition
     pub fn error(&self) -> Option<&str> {
         if self.reference.trim().is_empty() {
             return Some("Given device reference is empty or blank!");
@@ -19,14 +28,19 @@ impl DeviceInfo {
     }
 }
 
+/// Device identifier
 #[derive(Clone, Debug, serde::Serialize, serde::Deserialize, Eq, PartialEq, Hash)]
 pub struct DeviceId(pub String);
 
+/// Single device information
 #[derive(Clone, Debug, serde::Serialize, serde::Deserialize)]
 pub struct Device {
     /// The device ID
     pub id: DeviceId,
     /// Information about the device
+    ///
+    /// These information shall not be editable from the webui. They are automatically updated during
+    /// device synchronization
     pub info: DeviceInfo,
     /// Time at which device was initially enrolled
     pub time_create: u64,
@@ -42,6 +56,8 @@ pub struct Device {
     /// Specify whether the device is enabled or not
     pub enabled: bool,
     /// Information about the relays handled by the device
+    ///
+    /// There cannot be more than [info.max_relays] relays
     pub relays: Vec<DeviceRelay>,
 }
 
@@ -49,24 +65,38 @@ pub struct Device {
 /// time of a device
 #[derive(Clone, Debug, serde::Serialize, serde::Deserialize)]
 pub struct DailyMinRuntime {
+    /// Minimum time, in seconds, that this relay should run
     pub min_runtime: usize,
+    /// The seconds in the days (from 00:00) where the counter is reset
     pub reset_time: usize,
+    /// The hours during which the relay should be turned on to reach expected runtime
     pub catch_up_hours: Vec<usize>,
 }
 
 #[derive(Clone, Copy, Debug, serde::Serialize, serde::Deserialize, Eq, PartialEq)]
 pub struct DeviceRelayID(uuid::Uuid);
 
+/// Single device relay information
 #[derive(Clone, Debug, serde::Serialize, serde::Deserialize)]
 pub struct DeviceRelay {
+    /// Device relay id. Should be unique across the whole application
     id: DeviceRelayID,
+    /// Human-readable name for the relay
     name: String,
+    /// Whether this relay can be turned on or not
     enabled: bool,
+    /// Relay priority when selecting relays to turn of / on. 0 = lowest priority
     priority: usize,
+    /// Estimated consumption of the electrical equipment triggered by the relay
     consumption: usize,
+    /// Minimal time this relay shall be left on before it can be turned off
     minimal_uptime: usize,
+    /// Minimal time this relay shall be left off before it can be turned on again
     minimal_downtime: usize,
+    /// Optional minimal runtime requirements for this relay
     daily_runtime: Option<DailyMinRuntime>,
-    depends_on: Vec<DeviceRelay>,
-    conflicts_with: Vec<DeviceRelay>,
+    /// Specify relay that must be turned on before this relay can be started
+    depends_on: Vec<DeviceRelayID>,
+    /// Specify relays that must be turned off before this relay can be started
+    conflicts_with: Vec<DeviceRelayID>,
 }