Message interface

References to blocks and fields in a Message are defined by $message references. This type of reference is handled the same way as internal variables defined in the template. The difference is that the value of an internal variable is set by a #set directive, and the value of a $message reference is retrieved from the Message.

Message references are case sensitive

Message references are case sensitive. For example, $message.customer and $message.Customer are references to different fields.

Message references are strings

The value of a $message reference is always represented as a string.