How can I list only project specific workflow in dropdown list of "start workflow"

I am using AEM 6.4 want to list only project specific workflow in drop down list of "start workflow" and hide the out of the box workflows. Please suggest the best possible approach.

Solution:

Just add Workflow: System tag in the page properties of the OOTB workflow models. So it will hide all the OOTBS workflows from the drop-down list of Start Workflow option and it will only show the workflow models which do not contains workflow:System tag.

http://localhost:4502/libs/cq/workflow/admin/console/content/models.html

Here is the official documentation from Adobe in case if you want more on this https://helpx.adobe.com/in/experience-manager/kb/hide-workflow-models-start-workflow-list.html