diff --git a/lib/db.coffee b/lib/db.coffee
index 34fe66c..329a50d 100644
--- a/lib/db.coffee
+++ b/lib/db.coffee
@@ -275,7 +275,8 @@ fetchDevice = (id, timestamp, patterns, callback) ->
       else if k == '_tags'
         device['Tags'] ?= {'_timestamp': timestamp, '_writable': false, '_object': true}
         for t in v
-          device['Tags'][t] = {'_writable': false, '_value': true, '_type' : 'xsd:boolean', '_timestamp': timestamp}
+          t = t.replace(/[^a-zA-Z0-9\-]+/g, '_')
+          device['Tags'][t] = {'_writable': true, '_value': true, '_type' : 'xsd:boolean', '_timestamp': timestamp}
         delete device[k]
       else if k == '_deviceId'
         device['DeviceID'] ?= {'_timestamp': timestamp, '_writable': false, '_object': true}
@@ -343,14 +344,14 @@ saveDevice = (deviceId, deviceData, isNew, callback) ->
             when 'SerialNumber'
               update['$set']['_deviceId._SerialNumber'] = v
       when 'Tags'
-        if diff[2].value?[1][0] != diff[1].value?[1][0]
-          v = diff[2].value?[1][0]
+        if diff[2]?.value?[1]?[0] != diff[1]?.value?[1]?[0]
+          v = diff[2]?.value?[1][0]
           if v?
             update['$addToSet']['_tags'] ?= {'$each' : []}
-            update['$addToSet']['_tags']['$each'].push(v)
+            update['$addToSet']['_tags']['$each'].push(diff[0][1])
           else
             update['$pull']['_tags'] ?= {'$in' : []}
-            update['$pull']['_tags']['$in'].push(v)
+            update['$pull']['_tags']['$in'].push(diff[0][1])
       else
         if not diff[2]
           update['$unset'][diff[0].join('.')] = 1
diff --git a/lib/session.coffee b/lib/session.coffee
index 9e91331..06b4e95 100644
--- a/lib/session.coffee
+++ b/lib/session.coffee
@@ -315,6 +315,7 @@ runDeclarations = (sessionData, declarations) ->
     spv: new Map()
     gpn: new Set()
     gpnPatterns: new Map()
+    tags: new Map()
 
     virtualParameterDeclarations: []
     instancesToDelete: new Map()
@@ -494,6 +495,39 @@ rpcRequest = (sessionData, _declarations, callback) ->
         device.clearTrackers(sessionData.deviceData, 'prerequisite')
         return rpcRequest(sessionData, null, callback)
 
+      # Update tags
+      toClear = null
+      sessionData.syncState.tags.forEach((v, p) ->
+        c = sessionData.deviceData.attributes.get(p)
+        timestamp = sessionData.timestamp + sessionData.iteration + 1
+        if v and not c?
+          toClear = device.set(sessionData.deviceData, p, timestamp, {object: [timestamp, false], writable: [timestamp, true], value: [timestamp, [true, 'xsd:boolean']]}, toClear)
+        else if c? and not v
+          toClear = device.set(sessionData.deviceData, p, timestamp, toClear)
+          noMoreTags = true
+          iter = sessionData.deviceData.paths.subset(['Tags', '*'])
+          while p = iter.next().value
+            if sessionData.deviceData.attributes.has(p)
+              noMoreTags = false
+              break
+          if noMoreTags
+            toClear = device.set(sessionData.deviceData, ['Tags'], timestamp, null, toClear)
+      )
+
+      if toClear
+        return clear(sessionData, toClear, (err) ->
+          return callback(err) if err
+          if sessionData.deviceData.changes.has('prerequisite')
+            delete sessionData.syncState
+            device.clearTrackers(sessionData.deviceData, 'prerequisite')
+          return rpcRequest(sessionData, null, callback)
+        )
+
+      if sessionData.deviceData.changes.has('prerequisite')
+        delete sessionData.syncState
+        device.clearTrackers(sessionData.deviceData, 'prerequisite')
+        return rpcRequest(sessionData, null, callback)
+
       provisions = generateSetVirtualParameterProvisions(sessionData, sessionData.syncState.virtualParameterDeclarations[inception])
       if not provisions
         sessionData.rpcRequest = generateSetRpcRequest(sessionData)
@@ -824,6 +858,9 @@ processDeclarations = (sessionData, allDeclareTimestamps, allDeclareAttributeTim
         if currentPath.length == 1
           if declareAttributeValues.value?
             syncState.factoryReset = +(new Date(declareAttributeValues.value[0]))
+      when 'Tags'
+        if currentPath.length == 2 and currentPath.wildcard == 0 and declareAttributeValues?.value?
+          syncState.tags.set(currentPath, device.sanitizeParameterValue([declareAttributeValues.value[0], 'xsd:boolean'])[0])
       when 'VirtualParameters'
         if currentPath.length <= 2
           d = null