Optional / Is Specified

I don’t have exposure coding the Open Systems part of communication through EntireX. Below is a compatibility question I would like to know before I use the feature.
Does EntireX support the OPTIONAL keyword (in the Define Data) and the corresponding IS SPECIFIED logical condition in subprograms?
Does .NET and Java have a way to call the Natural subprogram to utilize these features?

Since I have not received any reply, I will assume that these are purely Natural features and EntireX has no support for it right now.

To make the subprogram work for all other languages other than Natural, I will simulate the Optional/Is Specified functionality. I will have to create additional parameter to indicate that these main parameters ‘are available’. For these instances blank or zero may not be an indication that the field was not specified, but are part of valid values that the parameter can be set.