Can anyone clarify, do these fields accept, java functions or are they simply a fixed generic field.  ie

Like:-

"Your Pet/s are due for an annual check up please check the attached file for details and the due date."

or can you use :-

functions:-

'Dear' [party:getPartyFullName(party:getPatientOwner(.))] ','

'You pet,' patient.entity.name ' is due for a annual checkup.  Please take a look at the attached pdf for the details and due dates'

OR

does it support any html markup(I didnt think so but thought I would ask)

Any ideas 
Ben