Within a user task, a segment of the embedded form markup is
...
<div class="form-group">
<label for="reference">Reference</label>
<input class="form-control"
cam-variable-name="reference"
cam-variable-type="String"
name="reference" />
</div>
...
On form entry, the reference field should be empty. On form submission, the associated Camunda process variable is populated with the reference text as a single String as expected.
Reading the Camunda manual, forums etc, there is no setting to specify the bound variable scope,
For this form field, I wish to use local variables (task scoped), not process instance scoped variables.
If process variables are used, if there is a following user task with a form using the same variable-name, that form field is populated with the previously entered value.
I understand that variables can be programmically reset and that I can use a different variable name but use of a local variable would avoid this.
Also, use of process variables results in an excessive number of variables as seen in
cockpit > running process instances > [process-name] > [instance GUID] > variables
Generally, unless the value is to be used later, form based variables have only relevance during form set-up and action processing.
To set local variables in user forms, the easiest way is to define them in a task-listener creating the task. Then you can reference the variables with cam-variable-name in the form.
Have a look at this post for further details: https://forum.camunda.org/t/variables-in-parallel-process/1476/3