diff --git a/silk-core/src/main/resources/org/silkframework/LinkSpecificationLanguage.xsd b/silk-core/src/main/resources/org/silkframework/LinkSpecificationLanguage.xsd
index 90f6c25d5d..04844ea63a 100644
--- a/silk-core/src/main/resources/org/silkframework/LinkSpecificationLanguage.xsd
+++ b/silk-core/src/main/resources/org/silkframework/LinkSpecificationLanguage.xsd
@@ -308,6 +308,8 @@
 
                 <xs:element ref="Outputs" minOccurs="0"/>
 
+                <xs:element name="ApplicationData" type="xs:string" minOccurs="0"/>
+
             </xs:sequence>
             <xs:attribute name="id" type="xs:string" use="required"/>
             <xs:attribute name="linkLimit" type="xs:string" />
diff --git a/silk-core/src/main/scala/org/silkframework/runtime/plugin/ParameterType.scala b/silk-core/src/main/scala/org/silkframework/runtime/plugin/ParameterType.scala
index 10ed89885b..a199c40868 100644
--- a/silk-core/src/main/scala/org/silkframework/runtime/plugin/ParameterType.scala
+++ b/silk-core/src/main/scala/org/silkframework/runtime/plugin/ParameterType.scala
@@ -183,7 +183,7 @@ object StringParameterType {
   private val allStaticTypes: Seq[StringParameterType[_]] = {
     Seq(StringType, CharType, IntType, DoubleType, BooleanType, IntOptionType, StringMapType, UriType, ResourceType,
       WritableResourceType, ResourceOptionType, DurationType, ProjectReferenceType, TaskReferenceType, MultilineStringParameterType, SparqlEndpointDatasetParameterType, LongType,
-      PasswordParameterType, IdentifierType, IdentifierOptionType, StringTraversableParameterType, RestrictionType)
+      PasswordParameterType, IdentifierType, IdentifierOptionType, StringTraversableParameterType, RestrictionType, StringOptionType)
   }
 
   /**
@@ -325,6 +325,25 @@ object StringParameterType {
     }
   }
 
+  object StringOptionType extends StringParameterType[StringOptionParameter] {
+
+    override def name: String = "option[string]"
+
+    override def description: String = "An optional non-empty string"
+
+    override def fromString(str: String)(implicit prefixes: Prefixes, resourceLoader: ResourceManager): StringOptionParameter = {
+      if(str.isEmpty) {
+        StringOptionParameter(None)
+      } else {
+        StringOptionParameter(Some(str))
+      }
+    }
+
+    override def toString(value: StringOptionParameter)(implicit prefixes: Prefixes): String = {
+      value.getOrElse("")
+    }
+  }
+
   object IdentifierOptionType extends StringParameterType[IdentifierOptionParameter] {
 
     override def name: String = "option[identifier]"
diff --git a/silk-core/src/main/scala/org/silkframework/runtime/plugin/StringOptionParameter.scala b/silk-core/src/main/scala/org/silkframework/runtime/plugin/StringOptionParameter.scala
new file mode 100644
index 0000000000..591304bf54
--- /dev/null
+++ b/silk-core/src/main/scala/org/silkframework/runtime/plugin/StringOptionParameter.scala
@@ -0,0 +1,11 @@
+package org.silkframework.runtime.plugin
+
+/**
+  * An optional string. Empty strings are interpreted as missing value.
+  */
+case class StringOptionParameter(value: Option[String])
+
+object StringOptionParameter {
+  implicit def toStringOptionParameter(v: Option[String]): StringOptionParameter = StringOptionParameter(v)
+  implicit def fromStringOptionParameter(v: StringOptionParameter): Option[String] = v.value
+}
diff --git a/silk-plugins/silk-serialization-json/src/main/scala/org/silkframework/serialization/json/JsonSerializers.scala b/silk-plugins/silk-serialization-json/src/main/scala/org/silkframework/serialization/json/JsonSerializers.scala
index ebc8cf4b87..b436528599 100644
--- a/silk-plugins/silk-serialization-json/src/main/scala/org/silkframework/serialization/json/JsonSerializers.scala
+++ b/silk-plugins/silk-serialization-json/src/main/scala/org/silkframework/serialization/json/JsonSerializers.scala
@@ -931,6 +931,7 @@ object JsonSerializers {
     final val REFERENCE_LINKS = "referenceLinks"
     final val LINK_LIMIT = "linkLimit"
     final val MATCHING_EXECUTION_TIMEOUT = "matchingExecutionTimeout"
+    final val APPLICATION_DATA = "applicationData"
 
     /** Deprecated properties */
     final val DEPRECATED_OUTPUTS = "outputs"
@@ -952,7 +953,8 @@ object JsonSerializers {
             output = stringValueOption(parametersObj, OUTPUT).filter(_.trim.nonEmpty).map(o => Identifier(o.trim)),
             referenceLinks = optionalValue(parametersObj, REFERENCE_LINKS).map(fromJson[ReferenceLinks]).getOrElse(ReferenceLinks.empty),
             linkLimit = numberValueOption(parametersObj, LINK_LIMIT).map(_.intValue).getOrElse(LinkSpec.DEFAULT_LINK_LIMIT),
-            matchingExecutionTimeout = numberValueOption(parametersObj, MATCHING_EXECUTION_TIMEOUT).map(_.intValue).getOrElse(LinkSpec.DEFAULT_EXECUTION_TIMEOUT_SECONDS)
+            matchingExecutionTimeout = numberValueOption(parametersObj, MATCHING_EXECUTION_TIMEOUT).map(_.intValue).getOrElse(LinkSpec.DEFAULT_EXECUTION_TIMEOUT_SECONDS),
+            applicationData = stringValueOption(parametersObj, APPLICATION_DATA)
           )
       }
     }
@@ -967,23 +969,30 @@ object JsonSerializers {
         output = mustBeJsArray(mustBeDefined(value, DEPRECATED_OUTPUTS))(_.value.map(v => Identifier(v.as[JsString].value))).headOption,
         referenceLinks = optionalValue(value, REFERENCE_LINKS).map(fromJson[ReferenceLinks]).getOrElse(ReferenceLinks.empty),
         linkLimit = numberValueOption(value, LINK_LIMIT).map(_.intValue()).getOrElse(LinkSpec.DEFAULT_LINK_LIMIT),
-        matchingExecutionTimeout = numberValueOption(value, MATCHING_EXECUTION_TIMEOUT).map(_.intValue()).getOrElse(LinkSpec.DEFAULT_EXECUTION_TIMEOUT_SECONDS)
+        matchingExecutionTimeout = numberValueOption(value, MATCHING_EXECUTION_TIMEOUT).map(_.intValue()).getOrElse(LinkSpec.DEFAULT_EXECUTION_TIMEOUT_SECONDS),
+        applicationData = stringValueOption(value, APPLICATION_DATA)
       )
     }
 
     override def write(value: LinkSpec)(implicit writeContext: WriteContext[JsValue]): JsValue = {
+      var parameters = Json.obj(
+        SOURCE -> toJson(value.dataSelections.source),
+        TARGET -> toJson(value.dataSelections.target),
+        RULE -> toJson(value.rule),
+        OUTPUT -> JsString(value.output.map(_.toString).getOrElse("")),
+        REFERENCE_LINKS -> toJson(value.referenceLinks),
+        LINK_LIMIT -> JsString(value.linkLimit.toString),
+        MATCHING_EXECUTION_TIMEOUT -> JsString(value.matchingExecutionTimeout.toString)
+      )
+
+      for(data <- value.applicationData) {
+        parameters += (APPLICATION_DATA -> JsString(data))
+      }
+
       Json.obj(
         TASKTYPE -> TASK_TYPE_LINKING,
         TYPE -> "linking",
-        PARAMETERS -> Json.obj(
-          SOURCE -> toJson(value.dataSelections.source),
-          TARGET -> toJson(value.dataSelections.target),
-          RULE -> toJson(value.rule),
-          OUTPUT -> JsString(value.output.map(_.toString).getOrElse("")),
-          REFERENCE_LINKS -> toJson(value.referenceLinks),
-          LINK_LIMIT -> JsString(value.linkLimit.toString),
-          MATCHING_EXECUTION_TIMEOUT -> JsString(value.matchingExecutionTimeout.toString)
-        )
+        PARAMETERS -> parameters
       )
     }
   }
diff --git a/silk-rules/src/main/scala/org/silkframework/rule/LinkSpec.scala b/silk-rules/src/main/scala/org/silkframework/rule/LinkSpec.scala
index 78162b928d..b2dc1f6268 100644
--- a/silk-rules/src/main/scala/org/silkframework/rule/LinkSpec.scala
+++ b/silk-rules/src/main/scala/org/silkframework/rule/LinkSpec.scala
@@ -25,7 +25,7 @@ import org.silkframework.rule.evaluation.ReferenceLinks
 import org.silkframework.rule.input.{Input, PathInput, TransformInput}
 import org.silkframework.rule.similarity.{Aggregation, Comparison, SimilarityOperator}
 import org.silkframework.runtime.activity.UserContext
-import org.silkframework.runtime.plugin.IdentifierOptionParameter
+import org.silkframework.runtime.plugin.{IdentifierOptionParameter, StringOptionParameter}
 import org.silkframework.runtime.plugin.annotations.{Param, Plugin}
 import org.silkframework.runtime.resource.Resource
 import org.silkframework.runtime.serialization.XmlSerialization._
@@ -35,7 +35,7 @@ import org.silkframework.util._
 import org.silkframework.workspace.project.task.DatasetTaskReferenceAutoCompletionProvider
 
 import scala.collection.mutable
-import scala.xml.Node
+import scala.xml.{Node, NodeSeq}
 
 /**
  * Represents a Silk Link Specification.
@@ -63,7 +63,10 @@ case class LinkSpec(@Param(label = "Source input", value = "The source input to
                     linkLimit: Int = LinkSpec.DEFAULT_LINK_LIMIT,
                     @Param(label = "Matching timeout", value = "The timeout for the matching phase. If the matching takes longer the execution will be stopped.",
                       advanced = true)
-                    matchingExecutionTimeout: Int = LinkSpec.DEFAULT_EXECUTION_TIMEOUT_SECONDS) extends TaskSpec {
+                    matchingExecutionTimeout: Int = LinkSpec.DEFAULT_EXECUTION_TIMEOUT_SECONDS,
+                    @Param(value = "Additional data that is set by the application managing the linking task.",
+                      visibleInDialog = false)
+                    applicationData: StringOptionParameter = None) extends TaskSpec {
 
   assert(linkLimit >= 0, "The link limit must be greater equal 0!")
   assert(matchingExecutionTimeout >= 0, "The matching execution timeout must be greater equal 0!")
@@ -238,7 +241,8 @@ object LinkSpec {
             Identifier(id)
           },
         linkLimit = (node \ "@linkLimit").headOption.map(_.text.toInt).getOrElse(LinkSpec.DEFAULT_LINK_LIMIT),
-        matchingExecutionTimeout = (node \ "@matchingExecutionTimeout").headOption.map(_.text.toInt).getOrElse(LinkSpec.DEFAULT_EXECUTION_TIMEOUT_SECONDS)
+        matchingExecutionTimeout = (node \ "@matchingExecutionTimeout").headOption.map(_.text.toInt).getOrElse(LinkSpec.DEFAULT_EXECUTION_TIMEOUT_SECONDS),
+        applicationData = (node \ "ApplicationData").headOption.map(_.text)
       )
     }
 
@@ -253,6 +257,7 @@ object LinkSpec {
         <Outputs>
           {spec.output.value.toSeq.map(o => <Output id={o}></Output>)}
         </Outputs>
+        { spec.applicationData.map(data => <ApplicationData>{data}</ApplicationData>).getOrElse(NodeSeq.Empty) }
       </Interlink>
   }
 }
diff --git a/silk-workbench/silk-workbench-workspace/test/controllers/workspace/TaskApiTest.scala b/silk-workbench/silk-workbench-workspace/test/controllers/workspace/TaskApiTest.scala
index 6be4d8382d..ebd3000d5e 100644
--- a/silk-workbench/silk-workbench-workspace/test/controllers/workspace/TaskApiTest.scala
+++ b/silk-workbench/silk-workbench-workspace/test/controllers/workspace/TaskApiTest.scala
@@ -260,6 +260,7 @@ class TaskApiTest extends PlaySpec with IntegrationTestTrait with MustMatchers {
     (response.json \ DATA \ PARAMETERS \ "source" \ "typeUri").get mustBe JsString("<http://dbpedia.org/ontology/Film>")
     (response.json \ DATA \ PARAMETERS \ "target" \ "typeUri").get mustBe JsString("<http://data.linkedmdb.org/resource/movie/film>")
     (response.json \ DATA \ PARAMETERS \ "rule" \ "linkType").get mustBe JsString("owl:sameAs")
+    (response.json \ DATA \ PARAMETERS \ "applicationData").isEmpty mustBe true
   }
 
   "patch linking task" in {
@@ -278,7 +279,8 @@ class TaskApiTest extends PlaySpec with IntegrationTestTrait with MustMatchers {
          |        "inputId": "$datasetId",
          |        "typeUri": "<urn:schema:targetType>",
          |        "restriction": ""
-         |      }
+         |      },
+         |      "applicationData": "Some Data"
          |    }
          |  }
          | }
@@ -297,6 +299,7 @@ class TaskApiTest extends PlaySpec with IntegrationTestTrait with MustMatchers {
     (response.json \ DATA \ PARAMETERS \ "source" \ "typeUri").get mustBe JsString("owl:Class")
     (response.json \ DATA \ PARAMETERS \ "target" \ "typeUri").get mustBe JsString("<urn:schema:targetType>")
     (response.json \ DATA \ PARAMETERS \ "rule" \ "linkType").get mustBe JsString("owl:sameAs")
+    (response.json \ DATA \ PARAMETERS \ "applicationData").get mustBe JsString("Some Data")
   }
 
   "post workflow task" in {
diff --git a/silk-workspace/src/test/scala/org/silkframework/workspace/WorkspaceProviderTestTrait.scala b/silk-workspace/src/test/scala/org/silkframework/workspace/WorkspaceProviderTestTrait.scala
index ab06ea6da9..45aceba146 100644
--- a/silk-workspace/src/test/scala/org/silkframework/workspace/WorkspaceProviderTestTrait.scala
+++ b/silk-workspace/src/test/scala/org/silkframework/workspace/WorkspaceProviderTestTrait.scala
@@ -80,6 +80,10 @@ trait WorkspaceProviderTestTrait extends FlatSpec with Matchers with MockitoSuga
       description = Some("Updated Task Description")
     )
 
+  val applicationData = "Some Data"
+
+  val applicationDataUpdated = "Updated Data"
+
   val dataset = PlainTask(DATASET_ID, DatasetSpec(MockDataset("default")), metaData = MetaData(DATASET_ID, Some(DATASET_ID + " description")))
 
   val datasetUpdated = PlainTask(DATASET_ID, DatasetSpec(MockDataset("updated"), uriAttribute = Some("uri")), metaData = MetaData(DATASET_ID))
@@ -88,11 +92,11 @@ trait WorkspaceProviderTestTrait extends FlatSpec with Matchers with MockitoSuga
   private val dummyRestriction = Restriction.custom("  ?a <urn:test:prop1> 1 .\n\n  ?a <urn:test:prop2> true .\n")(Prefixes.default)
 
   val linkSpec = LinkSpec(rule = rule, source = DatasetSelection(DUMMY_DATASET, dummyType, dummyRestriction), target = DatasetSelection(DUMMY_DATASET, dummyType, dummyRestriction),
-    linkLimit = LinkSpec.DEFAULT_LINK_LIMIT + 1, matchingExecutionTimeout = LinkSpec.DEFAULT_EXECUTION_TIMEOUT_SECONDS + 1)
+    linkLimit = LinkSpec.DEFAULT_LINK_LIMIT + 1, matchingExecutionTimeout = LinkSpec.DEFAULT_EXECUTION_TIMEOUT_SECONDS + 1, applicationData = Some(applicationData))
 
   val linkTask = PlainTask(LINKING_TASK_ID, linkSpec, metaData)
 
-  val linkTaskUpdated = PlainTask(LINKING_TASK_ID, LinkSpec(rule = rule.copy(operator = None)), metaDataUpdated)
+  val linkTaskUpdated = PlainTask(LINKING_TASK_ID, LinkSpec(rule = rule.copy(operator = None), applicationData = Some(applicationDataUpdated)), metaDataUpdated)
 
   val transformTask =
     PlainTask(