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The workflow will display various milestones (e.g. Sales Requirements), and each milestone has specific tasks that must be completed. A milestone approval request can be sent at any time by clicking Send For Approval.
A confirmation window will appear with an optional text field to add any notes. Click Send to submit the milestone for approval. 
The milestone status will change to "Pending Primary Approval" underneath the milestone name.
When the milestone has been approved, the milestone status will update to "Milestone Complete".
Note: Approval or completion of a milestone is not required before a user completes tasks on subsequent milestones in the workflow.
Related articles
You might also want to check out these related topics:
- How do I upload a contract or agreement to a quote?
- Where are notifications of a milestone waiting for approval sent?
- /wiki/spaces/SS/pages/1256699