What variables are available when creating a homefolder or share?

I received the following question from one of the folks that i have been working with:
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I am working on some home folder creation policies and have run into a particular server where the folder name format is ’firstname_lastname’ then is shared out as ‘username$’  Are there any variables/aliases I can use for first name and last name, similar to %username% ?
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I was wondering myself what other variables could be sued for the generation of the home folder or the share name.

Thanks,
-Alexi