DEM 
Events:

LS-Label generated: Triggered when a shipping label is generated.
LS-Shipped: Triggered when a package is in transit with the carrier.
LS-Delivered: Triggered when a package is successfully delivered.
LS-Out for delivery: Triggered when a package is out for delivery and expected to be delivered soon.
LS-Failed delivery: Triggered when a delivery attempt was unsuccessful.
LS-Delayed in transit: Triggered when a package is experiencing delays during transit.
LS-Unused labels: Triggered when a generated shipping label remains unused.
LS-Delayed delivery: Triggered when a package's delivery is delayed beyond the estimated timeframe.
LS-Lost/Damaged: Triggered when a package is lost or damaged during transit.
LS-Returned: Triggered when a package is returned to the sender.
LS-Predicted delays: Triggered when LateShipment predicts potential delays in the shipping process.
LS-Suspectedlost: Triggered when LateShipment suspects a package may be lost.
LS-Customer feedback - Post delivery: Triggered to gather customer feedback after a delivery is completed.

Merge tags:

Transactional\ShippingFirstName
Transactional\ShippingLastName
Transactional\ShippingStreetAddress1
Transactional\ShippingStreetAddress2
Transactional\ShippingCity
Transactional\ShippingState
Transactional\ShippingZip
Transactional\ShippingCountry
Transactional\ShippingPhone
Transactional\BillingFirstName
Transactional\BillingLastName
Transactional\BillingStreetAddress1
Transactional\BillingStreetAddress2
Transactional\BillingCity
Transactional\BillingState
Transactional\BillingZip
Transactional\BillingCountry
Transactional\BillingPhone
Transactional\OrderNumber
Transactional\TrackingNumber
Transactional\TrackingLink
Transactional\AccountLink
Transactional\OrderReviewLink
Transactional\ShippingMethod
Transactional\OrderDate
Transactional\EstimatedShipDate
Transactional\ShippingCost
Transactional\Discount
Transactional\GrandTotal
Transactional\ProductPrice1
Transactional\ProductQty1
Transactional\ProductSku1
Transactional\ProductTitle1
Transactional\ProductImageUrl1
Transactional\CartItems
Transactional\ShippingCompanyName
Transactional\BillingCompanyName
Transactional\CustomerID
Transactional\customername
Transactional\LSTrackingLink
Transactional\estimateddate
Transactional\carriertype
Transactional\lscartitems

Returns
Events:

Return Initiated (with shipping label) - When a return is approved and initiated
Return Initiated (without shipping label) - When a return is approved and when a return is initiated
Return In-Transit With Delay - When a return is delayed in transit
Return Received - Returned item received at the warehouse
Return Approved - Return request reported has been approved
Return Rejected - Return request reported has been denied

Merge Tags:

Transactional\customer_name
Transactional\return_id
Transactional\order_no 
Transactional\tracking_link
Transactional\product_name
Transactional\product_details
Transactional\racking_number
Transactional\link_to_shipping_label
Transactional\address
Transactional\product_status