diff --git a/src/server/data.rs b/src/server/data.rs
index af90b2c..378af17 100644
--- a/src/server/data.rs
+++ b/src/server/data.rs
@@ -92,9 +92,11 @@ bitflags! {
 	const NONE =      0;
 	/// This value should be cloned on write unless specified elsewhere.
 	const COW =       1<<0;
-	/// This should not show up in searches
+	/// This should not show up in searches.
 	const HIDDEN =    1<<1;
-	/// Versioning is enabled for this value
+	/// Versioning is enabled for this value.
+	///
+	/// When it is deleted, it should instead be moved away into a sperate entry.
 	const VERSIONED = 1<<2;
     }
 }
@@ -110,13 +112,15 @@ pub struct Info
 
     tags: Tags,
 
+    hooks: event::Hooks,
+
     owner: Option<Vec<user::EntityID>>, //starts as the user that created (i.e. same as `created_by`), or `None` if ownership is disabled
     signed: Option<Vec<Signature>>,
 
     perms: user::Permissions,
 
     created_by: user::UserID,
-    log: Vec<event::Event>,
+    log: Vec<event::InBandEvent>,
 }
 
 /// The root data containing map
diff --git a/src/server/event.rs b/src/server/event.rs
index 9f58618..b8cfec0 100644
--- a/src/server/event.rs
+++ b/src/server/event.rs
@@ -1,9 +1,10 @@
 //! When events happen to datamaps
 use super::*;
+use bitflags::bitflags;
 
-/// What happened in the event
+/// What happened in the in-band event
 #[derive(Debug, Serialize, Deserialize)]
-pub enum EventKind
+pub enum InBandEventKind
 {
     Created,
     Modified,
@@ -16,13 +17,84 @@ pub enum EventKind
     Comment(String),
 }
 
-/// An event that happened to a data entry
+/// An event that happened to a data entry that is then stored in its metadata.
+///
+/// # Note
+/// Not to be confused with `HookEvent`s
 #[derive(Debug, Serialize, Deserialize)]
-pub struct Event
+pub struct InBandEvent
 {
     who: Option<user::UserID>,
-    what: EventKind,
+    what: InBandEventKind,
     when: u64,
 
     signed: Option<cryptohelpers::rsa::Signature>,
 }
+
+
+bitflags! {
+    
+    /// Kind of events that should emmit for a hook
+    #[derive(Serialize, Deserialize)]
+    struct HookMask: u16
+    {
+	/// Filter all events. None are emiited.
+	const NONE =  0;
+	/// Mask any event, any kind is emitted.
+	const ANY  = !0;
+
+	/// Emmit read events.
+	const READ   = 1<<0;
+	/// Emmit write events.
+	const WRITE  = 1<<1;
+	/// Emmit delete events.
+	const DELETE = 1<<2;
+	
+	/// Propagate events from children of `Map` datas
+	const CHILD  = 1<<3;
+
+	/// Poke events are opaque events that are fired manually.
+	const POKE   = 1<<4;
+
+    }
+}
+
+impl Default for HookMask
+{
+    #[inline(always)]
+    fn default() -> Self
+    {
+	Self::NONE
+    }
+}
+
+
+/// Fire events when something happens to this value.
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Hooks
+{
+    filter: HookMask,
+}
+
+/// An event emitted from a matched `Hook`.
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Ord, PartialOrd)]
+pub enum HookEvent
+{
+    /// An opaque event type
+    Poke,
+    
+    Read,
+    Write,
+    Delete,
+    Child(Box<HookEvent>),
+}
+
+impl Default for HookEvent
+{
+    #[inline]
+    fn default() -> Self
+    {
+	Self::Poke
+    }
+}
+
diff --git a/src/server/user.rs b/src/server/user.rs
index f14e84f..09d8956 100644
--- a/src/server/user.rs
+++ b/src/server/user.rs
@@ -262,6 +262,15 @@ bitflags! {
     }
 }
 
+impl Default for Permission
+{
+    #[inline(always)]
+    fn default() -> Self
+    {
+	Self::READ
+    }
+}
+
 
 /// A set of permissions informations for users and/or groups
 #[derive(Debug, Serialize, Deserialize)]