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Promotional message is a space in which merchants will be able to place additional lines on to the customer receipt, up to 250 characters. Merchant's will be able to use this in a variety of ways, not just as an additional text feild but text field but as a way to interact with their customer base by including a QR code. Promotional Message can be filled in globally at store level or locally at POS level.
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Promotional Message is created under the store creation and modify in the hierarchy (management>hierarchy>modify>type:store) 
On the POS
If setting are set on the CAS it will pull those, these can always be changed from the POS though or added directly. On the POS the settings are found under the transaction tab. With these field the user will have the same amount of characters and spaces. A user could copy a QR code into the space and have that print instead of the promo text. 
Access
Is limited to System Admin, and managers for the CAS. On the POS store managers and higher with access to login will be able to mdify