You can create a checkbox field for each value of a multi-value picklist field. The checkbox is selected if the field contains the value included in the syntax.

Syntax{{CHECKBOX:FieldName:Value}}
ValuesFieldName is the merge field to evaluate.

Value determines whether to select or clear the checkbox.

Usage

{{CHECKBOX:Flavors:Chocolate}} Chocolate

{{CHECKBOX:Flavors:Vanilla}} Vanilla
{{CHECKBOX:Flavors:Banana}} Banana

On merge:

 Chocolate

 Vanilla

 Banana

For field values that contain Dashes, you must enclose the entire Merge Field in double-quotes. For example, Value is Strawberry-Banana. Your merge field should look like this:

{{"CHECKBOX:Flavors:Strawberry-Banana"}}

If the field contains spaces, you do not need to enclose the field in quotation marks.