Attribute Name User Parameter

'Attribute Name' became available as a user parameter type since FME 2013, I was waiting for this functionality.
When using this parameter type, we have to be aware that the parameter value is not attribute value but attribute name. Those seem to be mixed up sometimes.
Community > Retrieving Parameter Attribute Values
Community > Should Attributes in Parameters be pointers?

When the parameter type is 'Attribute Name',
'$(PARAM_NAME)' represents the parameter value i.e. an attribute name,
'@Value($(PARAM_NAME))' represents the value which the attribute name refers to.
Let's keep this in mind, all is going well!