--- a/src/iconolab/models.py	Thu Dec 15 16:35:01 2016 +0100
+++ b/src/iconolab/models.py	Fri Dec 16 11:35:10 2016 +0100
@@ -313,7 +313,17 @@
         that will be displayed by default in most pages. 
         
         Annotation data (title, description, fragment) is thus stored in the revision.
+        
+        Annotations can be considered validated or not depending on the metacategories posted in their comments through the attribute validation_state. Their validation state
+        can also be overriden and in such case we can use validation_state_overriden attribute to remember it in the model (so for instance if an admin un-validates an annotation
+        we could block it from being validated again)
     """
+    UNVALIDATED = 0
+    VALIDATED = 1
+    VALIDATION_STATES = (
+        (UNVALIDATED, 'unvalidated'),
+        (VALIDATED, 'validated'),
+    )
     annotation_guid = models.UUIDField(default=uuid.uuid4, editable=False)
     image = models.ForeignKey('Image', related_name='annotations', on_delete=models.CASCADE)
     source_revision = models.ForeignKey('AnnotationRevision', related_name='source_related_annotation', blank=True, null=True)
@@ -321,6 +331,8 @@
     author = models.ForeignKey(User, null=True)
     created = models.DateTimeField(auto_now_add=True, null=True)
     comments = GenericRelation('IconolabComment', content_type_field='content_type_id', object_id_field='object_pk')
+    validation_state = models.IntegerField(choices=VALIDATION_STATES, default=UNVALIDATED)
+    validation_state_overriden = models.BooleanField(default=False)
     
     objects = AnnotationManager()
     
@@ -769,12 +781,18 @@
             - CONTRIBUTORS : Notifies contributors (revision owners) on target annotation
             - COMMENTERS : Notifies commenters (contributors + comment owners) on target annotation
             - COLLECTION_ADMINS : Notifies collection admins
+            
+        Metacategories can be used to consider an annotation as "validated" if a certain agreement threshold is reached using their validation_value property
+        
+            - NEUTRAL : The metacategory doesn't affect the validation state
+            - AGREEMENT : The metacategory can be used to validate the annotation when linked to a comment on said annotation
+            - DISAGREEMENT : The metacategory can be used to unvalidate the annotation when linked to a comment on said annotation
+   
     """
     NONE = 0
     CONTRIBUTORS = 1
     COMMENTERS = 2
     COLLECTION_ADMINS = 3
-    
     NOTIFIED_USERS = (
         (NONE, 'none'),
         (CONTRIBUTORS, 'contributors'),
@@ -782,9 +800,19 @@
         (COLLECTION_ADMINS, 'collection admins'),
     )
     
+    NEUTRAL = 0
+    AGREEMENT = 1
+    DISAGREEMENT = 2
+    VALIDATION_VALUES = (
+        (NEUTRAL, 'neutral'),
+        (AGREEMENT, 'agreement'),
+        (DISAGREEMENT, 'disagreement'),
+    )
+    
     collection = models.ForeignKey(Collection, related_name="metacategories")
     label = models.CharField(max_length=255)
     triggers_notifications = models.IntegerField(choices=NOTIFIED_USERS, default=NONE)
+    validation_value = models.IntegerField(choices=VALIDATION_VALUES, default=NEUTRAL)
     
     def __str__(self):
         return self.label