> ## Documentation Index
> Fetch the complete documentation index at: https://docs.aseeflow.org/llms.txt
> Use this file to discover all available pages before exploring further.

# ASEE Flow BPMN Extension Elements

The following attributes are extension attributes for the `camunda` namespace `http://camunda.org/schema/1.0/bpmn`.

## connector

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> The configuration of a camunda connector. </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2">–</td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The [ camunda:connectorId](/reference/bpmn20/custom-extensions/extension-elements#connectorid) child element is required and must identify a connector implementation known to the process engine </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [Service Task](/reference/bpmn20/tasks/service-task), [Business Rule Task](/reference/bpmn20/tasks/business-rule-task), [Send Task](/reference/bpmn20/tasks/send-task), Message Event Definition of [ Message Intermediate Throwing Event](/reference/bpmn20/events/message-events#message-intermediate-throwing-event) or [Message End Event](/reference/bpmn20/events/message-events#message-end-event), </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [ camunda:inputOutput](/reference/bpmn20/custom-extensions/extension-elements#inputoutput), [ camunda:connectorId](/reference/bpmn20/custom-extensions/extension-elements#connectorid) </td> </tr>
</table>

## connectorId

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> The unique identifier of the connector type to instantiate. </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2">–</td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The connector type has to be known to the process engine </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [ camunda:connector](/reference/bpmn20/custom-extensions/extension-elements#connector) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2">–</td> </tr>
</table>

## constraint

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Metadata of an individual validation constraint for a form field (see [Form Field Validation](/user-guide/task-forms#form-field-validation)). </td> </tr>
  <tr> <th>Attributes</th> <td><code>name</code></td> <td> The name of the form field constraint type </td> </tr>
  <tr> <td /> <td><code>config</code></td> <td> The configuration of the form field constraint type </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The <code>name</code> attribute must be one of the known validators (<code>required</code>, <code>minlength</code>, <code>maxlength</code>, <code>min</code>, <code>max</code>, <code>readonly</code> or <code>validator</code>) </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [camunda:validation](/reference/bpmn20/custom-extensions/extension-elements#validation) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> – </td> </tr>
</table>

## entry

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> A single entry of a map structure. The value can be a constant, expression, script, list or another map. </td> </tr>
  <tr> <th>Attributes</th> <td><code>key</code></td> <td> The key of the entry in the map. Can be a string or an expression. </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The <code>key</code> attribute is required </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [camunda:map](/reference/bpmn20/custom-extensions/extension-elements#map) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [camunda:list](/reference/bpmn20/custom-extensions/extension-elements#list), [camunda:map](/reference/bpmn20/custom-extensions/extension-elements#map), [camunda:script](/reference/bpmn20/custom-extensions/extension-elements#script) </td> </tr>
</table>

## errorEventDefinition

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Definition of an error event that can be triggered by an expression. This element extends the [errorEventDefinition](/reference/bpmn20/events/error-events#defining-an-error) element from the bpmn namespace inheriting all of its attributes: <code>id</code>, <code>errorRef</code> </td> </tr>
  <tr> <th>Attributes</th> <td><code>expression</code></td> <td> An expression that will trigger the error if it evaluates to <code>true</code>. </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The <code>errorRef</code> attribute is required </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [Service Task](/reference/bpmn20/tasks/service-task) of type <code>external</code> </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> – </td> </tr>
</table>

## executionListener

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Add an execution listener to an event. </td> </tr>
  <tr> <th>Attributes</th> <td><code>event</code></td> <td> The type of the event for which the listener is called </td> </tr>
  <tr> <td /> <td><code>class</code></td> <td> see [camunda:class](/reference/bpmn20/custom-extensions/extension-attributes#class) </td> </tr>
  <tr> <td /> <td><code>expression</code></td> <td> see [camunda:expression](/reference/bpmn20/custom-extensions/extension-attributes#expression) </td> </tr>
  <tr> <td /> <td><code>delegateExpression</code></td> <td> see [camunda:delegateExpression](/reference/bpmn20/custom-extensions/extension-attributes#delegateexpression) </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The <code>event</code> attribute is required (except for transitions) and must be one of the task events: <code>start</code> or <code>end</code> </td> </tr>
  <tr> <td /> <td colspan="2"> One of the attributes <code>class</code>, <code>expression</code> or <code>delegateExpression</code> is mandatory </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> Process, Task, [Service Task](/reference/bpmn20/tasks/service-task), [Send Task](/reference/bpmn20/tasks/send-task), [User Task](/reference/bpmn20/tasks/user-task), [Business Rule Task](/reference/bpmn20/tasks/business-rule-task), [Script Task](/reference/bpmn20/tasks/script-task), [Receive Task](/reference/bpmn20/tasks/receive-task), [Manual Task](/reference/bpmn20/tasks/manual-task), [Exclusive Gateway](/reference/bpmn20/gateways/exclusive-gateway), [Sequence Flow](/reference/bpmn20/gateways/sequence-flow), [Parallel Gateway](/reference/bpmn20/gateways/parallel-gateway), [Inclusive Gateway](/reference/bpmn20/gateways/inclusive-gateway), [Event Based Gateway](/reference/bpmn20/gateways/event-based-gateway), [Start Event](/reference/bpmn20/events/start-events), [Intermediate Catch Event](/reference/bpmn20/events), [Intermediate Throw Event](/reference/bpmn20/events), [End Events](/reference/bpmn20/events), [Boundary Events](/reference/bpmn20/events), [Embedded Subprocess](/reference/bpmn20/subprocesses/embedded-subprocess), [Call Activity](/reference/bpmn20/subprocesses/call-activity), [Event Subprocess](/reference/bpmn20/subprocesses/event-subprocess), [Transaction Subprocess](/reference/bpmn20/subprocesses/transaction-subprocess) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [camunda:field](/reference/bpmn20/custom-extensions/extension-elements#field), [camunda:script](/reference/bpmn20/custom-extensions/extension-elements#script) </td> </tr>
</table>

## expression

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Defines an expression to inject in delegated classes (see [Field Injection](/user-guide/process-engine/delegation-code#field-injection)). </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Text Content</th> <td colspan="2"> The expression to inject </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [camunda:field](/reference/bpmn20/custom-extensions/extension-elements#field) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> – </td> </tr>
</table>

## failedJobRetryTimeCycle

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Defines the custom retry schedule for a failed job (see [Failed Jobs](/user-guide/process-engine/the-job-executor#failed-jobs)). </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Text Content</th> <td colspan="2"> The retry time cycle value or expression </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The configuration follows the [ISO 8601 standard for repeating time intervals](http://en.wikipedia.org/wiki/ISO_8601#Repeating_intervals) </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> Task, [Service Task](/reference/bpmn20/tasks/service-task), [Send Task](/reference/bpmn20/tasks/send-task), [User Task](/reference/bpmn20/tasks/user-task), [Business Rule Task](/reference/bpmn20/tasks/business-rule-task), [Script Task](/reference/bpmn20/tasks/script-task), [Receive Task](/reference/bpmn20/tasks/receive-task), [Timer Start Event](/reference/bpmn20/events/timer-events#timer-start-event), [Timer Intermediate Catching Event](/reference/bpmn20/events/timer-events#timer-intermediate-catching-event), [Timer Boundary Event](/reference/bpmn20/events/timer-events#timer-boundary-event), [Intermediate Signal Throw Event](/reference/bpmn20/events/signal-events), [Embedded Subprocess](/reference/bpmn20/subprocesses/embedded-subprocess), [Call Activity](/reference/bpmn20/subprocesses/call-activity), [Transaction Subprocess](/reference/bpmn20/subprocesses/transaction-subprocess), [Multi Instance Loop Characteristics](/reference/bpmn20/tasks/task-markers#multiple-instance) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> – </td> </tr>
</table>

## field

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Defines the value to inject in delegated classes (see [Field Injection](/user-guide/process-engine/delegation-code#field-injection)). </td> </tr>
  <tr> <th>Attributes</th> <td><code>name</code></td> <td> The name of the field </td> </tr>
  <tr> <td /> <td><code>expression</code></td> <td>The value of the field as expression</td> </tr>
  <tr> <td /> <td><code>stringValue</code></td> <td>The value of the field as String</td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> Only one attribute of <code>stringValue</code> and <code>expression</code> or one of the child elements <code>string</code> and <code>expression</code> can be used </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [Service Task](/reference/bpmn20/tasks/service-task), [Business Rule Task](/reference/bpmn20/tasks/business-rule-task), [Send Task](/reference/bpmn20/tasks/send-task), Message Event Definition of [Message Intermediate Throwing Event](/reference/bpmn20/events/message-events#message-intermediate-throwing-event) or [Message End Event](/reference/bpmn20/events/message-events#message-end-event), [camunda:taskListener](/reference/bpmn20/custom-extensions/extension-elements#tasklistener), [camunda:executionListner](/reference/bpmn20/custom-extensions/extension-elements#executionlistener) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [camunda:expression](/reference/bpmn20/custom-extensions/extension-elements#expression), [camunda:string](/reference/bpmn20/custom-extensions/extension-elements#string) </td> </tr>
</table>

## formData

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Metadata to define fields of a form, which are used to generate task forms (see [Generated Task Forms](/user-guide/task-forms#generated-task-forms)). </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [Start Event](/reference/bpmn20/events/start-events), [User Task](/reference/bpmn20/tasks/user-task) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [camunda:formField](/reference/bpmn20/custom-extensions/extension-elements#formfield) </td> </tr>
</table>

## formField

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Metadata to define a single form field (see [Generated Task Forms](/user-guide/task-forms#generated-task-forms)). </td> </tr>
  <tr> <th>Attributes</th> <td><code>id</code></td> <td> The id of the form field, corresponding to the name of a process variable </td> </tr>
  <tr> <td /> <td><code>label</code></td> <td> The label to be displayed next to the form field </td> </tr>
  <tr> <td /> <td><code>type</code></td> <td> The type of the form field </td> </tr>
  <tr> <td /> <td><code>datePattern</code></td> <td> The pattern of a date type form field </td> </tr>
  <tr> <td /> <td><code>defaultValue</code></td> <td> The value to be used as a default (pre-selection) for the field </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The attribute <code>id</code> may not be empty </td> </tr>
  <tr> <td /> <td colspan="2"> The attribute <code>type</code> can be one of the known form field types (<code>string</code>, <code>long</code>, <code>boolean</code>, <code>date</code> or <code>enum</code>) or a custom one </td> </tr>
  <tr> <td /> <td colspan="2"> The attribute <code>datePattern</code> can only be used if the <code>type</code> attribute is set to <code>date</code> </td> </tr>
  <tr> <td /> <td colspan="2"> The child element <code>camunda:properties</code> is only allowed once </td> </tr>
  <tr> <td /> <td colspan="2"> The child element <code>camunda:validation</code> is only allowed once </td> </tr>
  <tr> <td /> <td colspan="2"> The child elements <code>camunda:values</code> can only be used if the <code>type</code> attribute is set to <code>enum</code> </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [camunda:formData](/reference/bpmn20/custom-extensions/extension-elements#formdata) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [camunda:properties](/reference/bpmn20/custom-extensions/extension-elements#properties), [camunda:validation](/reference/bpmn20/custom-extensions/extension-elements#validation), [camunda:value](/reference/bpmn20/custom-extensions/extension-elements#value) </td> </tr>
</table>

## formProperty

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Metadata to define a form field (<strong>Deprecated</strong>, use [camunda:formData](/reference/bpmn20/custom-extensions/extension-elements#formdata)). </td> </tr>
  <tr> <th>Attributes</th> <td><code>id</code></td> <td> The key used to submit the property through the API </td> </tr>
  <tr> <td /> <td><code>name</code></td> <td> The display label of the property </td> </tr>
  <tr> <td /> <td><code>type</code></td> <td> The type of the property </td> </tr>
  <tr> <td /> <td><code>required</code></td> <td> True if the form field is required (default: <code>false</code>) </td> </tr>
  <tr> <td /> <td><code>readable</code></td> <td> True if the form field is readable and will be displayed (default: <code>true</code>) </td> </tr>
  <tr> <td /> <td><code>writeable</code></td> <td> True if the form field is writeable (default: <code>true</code>) </td> </tr>
  <tr> <td /> <td><code>variable</code></td> <td> Specifies the process variable on which the variable is mapped </td> </tr>
  <tr> <td /> <td><code>expression</code></td> <td> Specifies an expression that maps the property, e.g., <code>\$\{street.address}</code> </td> </tr>
  <tr> <td /> <td><code>datePattern</code></td> <td> The pattern of a date type form field </td> </tr>
  <tr> <td /> <td><code>default</code></td> <td> The default value or expression of the property </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The <code>id</code> attribute is required </td> </tr>
  <tr> <td /> <td colspan="2"> The attribute <code>type</code> can be one of the known types (<code>string</code>, <code>long</code>, <code>boolean</code>, <code>date</code> or <code>enum</code>) or a custom one </td> </tr>
  <tr> <td /> <td colspan="2"> The attribute <code>datePattern</code> can only be used if the <code>type</code> attribute is set to <code>date</code> </td> </tr>
  <tr> <td /> <td colspan="2"> The child elements <code>camunda:values</code> can only be used if the <code>type</code> attribute is set to <code>enum</code> </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [Start Event](/reference/bpmn20/events/start-events), [User Task](/reference/bpmn20/tasks/user-task) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [camunda:value](/reference/bpmn20/custom-extensions/extension-elements#value) </td> </tr>
</table>

## in

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> The element specifies variables which should be passed to the subprocess, see [passing variables](/reference/bpmn20/subprocesses/call-activity#passing-variables) for more information. </td> </tr>
  <tr> <th>Attributes</th> <td><code>source</code></td> <td> A name of a process variable to be passed in </td> </tr>
  <tr> <td /> <td><code>sourceExpression</code></td> <td> An expression to be evaluated and passed in </td> </tr>
  <tr> <td /> <td><code>variables</code></td> <td> Can be set to <code>all</code> to pass all process variables in </td> </tr>
  <tr> <td /> <td><code>target</code></td> <td> Name of the process variable inside the subprocess instance </td> </tr>
  <tr> <td /> <td><code>local</code></td> <td> Can be set to <code>true</code> to only pass local variables of the execution that executes the call activity. </td> </tr>
  <tr> <td /> <td><code>businessKey</code></td> <td> Set the business key of the subprocess process instance </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> Only one of the attributes <code>source</code>, <code>sourceExpression</code>, <code>variables</code> or <code>businessKey</code> can be used </td> </tr>
  <tr> <td /> <td colspan="2"> The attribute <code>target</code> is required if the <code>source</code> or <code>sourceExpression</code> attribute is used </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [Call Activity](/reference/bpmn20/subprocesses/call-activity), [Signal Events (in Intermediate and End Throwing Events)](/reference/bpmn20/events/signal-events) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> – </td> </tr>
</table>

## inputParameter

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> An single input mapping for the activity. If the element has no child element, the text content of this element is mapped into the activity. The text content can be a constant string value or an expression. If no child element or text content exists, the variable inside the activity is set to the special value <code>null</code>. </td> </tr>
  <tr> <th>Attributes</th> <td><code>name</code></td> <td> The name of the variable inside the activity. </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The <code>name</code> attribute is required. </td> </tr>
  <tr> <td /> <td colspan="2"> The element can have one child element, a constant string or an expression as text content. </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [ camunda:inputOutput](/reference/bpmn20/custom-extensions/extension-elements#inputoutput) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [ camunda:list](/reference/bpmn20/custom-extensions/extension-elements#list), [ camunda:map](/reference/bpmn20/custom-extensions/extension-elements#map), [ camunda:script](/reference/bpmn20/custom-extensions/extension-elements#script) </td> </tr>
</table>

## inputOutput

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> The element describes an input/output mapping for the activity. </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [All Tasks](/reference/bpmn20/tasks), [All Events](/reference/bpmn20/events) (except Start and Boundary Events), [Call Activity](/reference/bpmn20/subprocesses/call-activity), [Embedded Subprocess](/reference/bpmn20/subprocesses/embedded-subprocess), [Transaction Subprocess](/reference/bpmn20/subprocesses/transaction-subprocess), [ camunda:connector](/reference/bpmn20/custom-extensions/extension-elements#connector) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [ camunda:inputParameter](/reference/bpmn20/custom-extensions/extension-elements#inputparameter), [ camunda:outputParameter](/reference/bpmn20/custom-extensions/extension-elements#outputparameter) </td> </tr>
</table>

## list

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> A list structure. If the list contains multiple values, they should be added as text content of child elements. Which child elements are used is arbitrary, e.g.,: <code><br /> \<camunda:list><br />   \<camunda:value>one\</camunda:value><br />   \<camunda:value>two\</camunda:value><br />   \<camunda:value>three\</camunda:value><br /> \</camunda:list></code><br /> A [ camunda:script](/reference/bpmn20/custom-extensions/extension-elements#script) element can also be used as a list element. The return value of the script is added to the list. Furthermore, lists can contain nested lists and maps. </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> Multiple values have to be encapsulated in child elements. </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [ camunda:inputParameter](/reference/bpmn20/custom-extensions/extension-elements#inputparameter), [ camunda:outputParameter](/reference/bpmn20/custom-extensions/extension-elements#outputparameter), [camunda:list](/reference/bpmn20/custom-extensions/extension-elements#list), [camunda:entry](/reference/bpmn20/custom-extensions/extension-elements#entry) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> Any child element, [ camunda:list](/reference/bpmn20/custom-extensions/extension-elements#list), [ camunda:map](/reference/bpmn20/custom-extensions/extension-elements#map) </td> </tr>
</table>

## map

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> A map structure. The entries can be constants, expressions, scripts, nested maps and lists. </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [ camunda:inputParameter](/reference/bpmn20/custom-extensions/extension-elements#inputparameter), [ camunda:outputParameter](/reference/bpmn20/custom-extensions/extension-elements#outputparameter), [camunda:list](/reference/bpmn20/custom-extensions/extension-elements#list), [camunda:entry](/reference/bpmn20/custom-extensions/extension-elements#entry) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [camunda:entry](/reference/bpmn20/custom-extensions/extension-elements#entry) </td> </tr>
</table>

## out

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> The element specifies variables which should be passed back from the subprocess, see [passing variables](/reference/bpmn20/subprocesses/call-activity#passing-variables) for more information. </td> </tr>
  <tr> <th>Attributes</th> <td><code>source</code></td> <td> A name of a process variable to be passed back </td> </tr>
  <tr> <td /> <td><code>sourceExpression</code></td> <td> An expression to be evaluated and passed back </td> </tr>
  <tr> <td /> <td><code>variables</code></td> <td> Can be set to <code>all</code> to pass all subprocess variables back </td> </tr>
  <tr> <td /> <td><code>target</code></td> <td> Name of the process variable inside the subprocess instance </td> </tr>
  <tr> <td /> <td><code>local</code></td> <td> Can be set to <code>true</code> to pass variables from the called case/process instance to local variables of the execution executing the call activity. </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> Only one of the attributes <code>source</code>, <code>sourceExpression</code> or <code>variables</code> can be used </td> </tr>
  <tr> <td /> <td colspan="2"> The attribute <code>target</code> is required if the <code>source</code> or <code>sourceExpression</code> attribute is used </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [Call Activity](/reference/bpmn20/subprocesses/call-activity) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> – </td> </tr>
</table>

## outputParameter

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> An single output mapping for the activity. If the element has no child element, the text content of this element is mapped out of the activity. The text content can be a constant string value or an expression. If no child element or text content exists, the variable outside of the activity is set to the special value <code>null</code>. </td> </tr>
  <tr> <th>Attributes</th> <td><code>name</code></td> <td> The name of the variable outside of the activity. </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The <code>name</code> attribute is required. </td> </tr>
  <tr> <td /> <td colspan="2"> The element can have one child element, a constant string or an expression as text content. </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [ camunda:inputOutput](/reference/bpmn20/custom-extensions/extension-elements#inputoutput) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [ camunda:list](/reference/bpmn20/custom-extensions/extension-elements#list), [ camunda:map](/reference/bpmn20/custom-extensions/extension-elements#map), [ camunda:script](/reference/bpmn20/custom-extensions/extension-elements#script) </td> </tr>
</table>

## potentialStarter

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Defines which users or groups can start the process. </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> Process </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> resourceAssignmentExpression </td> </tr>
</table>

## properties

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> A key value list of properties which be can be interpreted freely. </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> Base Element, [camunda:formField](/reference/bpmn20/custom-extensions/extension-elements#formfield) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [camunda:property](/reference/bpmn20/custom-extensions/extension-elements#property) </td> </tr>
</table>

## property

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> A key value pair which can be interpreted freely. </td> </tr>
  <tr> <th>Attributes</th> <td><code>id</code></td> <td> The id of the form field property </td> </tr>
  <tr> <td /> <td><code>name</code></td> <td> The name of the property </td> </tr>
  <tr> <td /> <td><code>value</code></td> <td> The value of the property </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> If the property belongs to a <code>camunda:formField</code> extension element, only the attributes <code>id</code> and <code>value</code> are used. </td> </tr>
  <tr> <td /> <td colspan="2"> If the parent <code>camunda:properties</code> element is directly added as an extension element, for example by the camunda Modeler, only the attributes <code>name</code> and <code>value</code> are used. </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [camunda:properties](/reference/bpmn20/custom-extensions/extension-elements#properties) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> – </td> </tr>
</table>

## script

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> A script element. The script is executed and the return value is used as mapping value. </td> </tr>
  <tr> <th>Attributes</th> <td><code>scriptFormat</code></td> <td> The format identifier, normally the language of the script source code </td> </tr>
  <tr> <td /> <td><code>resource</code></td> <td> equivalent to [ camunda:resource](/reference/bpmn20/custom-extensions/extension-attributes#resource) </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The <code>scriptFormat</code> attribute is required </td> </tr>
  <tr> <td /> <td colspan="2"> If the <code>resource</code> attribute is used, no source code text content is allowed </td> </tr>

  <tr />

  <tr> <th>Parent elements</th> <td colspan="2"> [ camunda:inputParameter](/reference/bpmn20/custom-extensions/extension-elements#inputparameter), [ camunda:outputParameter](/reference/bpmn20/custom-extensions/extension-elements#outputparameter), [camunda:entry](/reference/bpmn20/custom-extensions/extension-elements#entry), [camunda:list](/reference/bpmn20/custom-extensions/extension-elements#list), [ camunda:executionListener](/reference/bpmn20/custom-extensions/extension-elements#executionlistener), [ camunda:taskListener](/reference/bpmn20/custom-extensions/extension-elements#tasklistener) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> – </td> </tr>
</table>

## string

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Defines a String value to inject in delegated classes (see [Field Injection](/user-guide/process-engine/delegation-code#field-injection)). </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Text Content</th> <td colspan="2"> The String value to inject </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [camunda:field](/reference/bpmn20/custom-extensions/extension-elements#field) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> – </td> </tr>
</table>

## taskListener

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Adds a task listener to a task event. </td> </tr>
  <tr> <th>Attributes</th> <td><code>event</code></td> <td> The type of the event for which the listener is called </td> </tr>
  <tr> <td /> <td><code>class</code></td> <td> see [camunda:class](/reference/bpmn20/custom-extensions/extension-attributes#class) </td> </tr>
  <tr> <td /> <td><code>expression</code></td> <td> see [camunda:expression](/reference/bpmn20/custom-extensions/extension-attributes#expression) </td> </tr>
  <tr> <td /> <td><code>delegateExpression</code></td> <td> see [camunda:delegateExpression](/reference/bpmn20/custom-extensions/extension-attributes#delegateexpression) </td> </tr>
  <tr> <td /> <td><code>id</code></td> <td> The id of the task listener in the parent scope, only required when <code>event</code> is set to <code>timeout</code> </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> The <code>event</code> attribute is required and must be one of the task events: <code>create</code>, <code>assignment</code>, <code>update</code>, <code>complete</code>, <code>delete</code> or <code>timeout</code> </td> </tr>
  <tr> <td /> <td colspan="2"> One of the attributes <code>class</code>, <code>expression</code> or <code>delegateExpression</code> is mandatory </td> </tr>
  <tr> <td /> <td colspan="2"> If the attribute <code>event</code> is set to <code>timeout</code>, the attribute <code>id</code> and exactly one child element of type [timerEventDefinition](/reference/bpmn20/events/timer-events#defining-a-timer) are mandatory </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [User Task](/reference/bpmn20/tasks/user-task) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [camunda:field](/reference/bpmn20/custom-extensions/extension-elements#field), [camunda:script](/reference/bpmn20/custom-extensions/extension-elements#script), [timerEventDefinition](/reference/bpmn20/events/timer-events#defining-a-timer) </td> </tr>
</table>

## validation

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Metadata to define a list of validation constraints for form fields (see [Form Field Validation](/user-guide/task-forms#form-field-validation)). </td> </tr>
  <tr> <th>Attributes</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [camunda:formField](/reference/bpmn20/custom-extensions/extension-elements#formfield) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> [camunda:constraint](/reference/bpmn20/custom-extensions/extension-elements#constraint) </td> </tr>
</table>

## value

<table class="table table-striped">
  <tr> <th>Description</th> <td colspan="2"> Possible values of a form field with the type <code>enum</code>. </td> </tr>
  <tr> <th>Attributes</th> <td><code>id</code></td> <td> The id of the value </td> </tr>
  <tr> <td /> <td><code>name</code></td> <td> The name of the value </td> </tr>
  <tr> <th>Constraints</th> <td colspan="2"> – </td> </tr>
  <tr> <th>Parent elements</th> <td colspan="2"> [camunda:formField](/reference/bpmn20/custom-extensions/extension-elements#formfield), [camunda:formProperty](/reference/bpmn20/custom-extensions/extension-elements#formproperty) </td> </tr>
  <tr> <th>Child elements</th> <td colspan="2"> – </td> </tr>
</table>