Tag Type C++ code (built in to libHForm/
Attributes None.
Contained Tags VarOne or more.
Related Tags Var tags to be exchanged with the outside world should go in the Public section instead. Both of these sections are ignored unless they occur within the Head section.

The {Private} ... {/Private} section just contains a list of {Var} tags. Here's an example that loads five variables from a par file. Note how you can omit the loc=... attribute after the first line:
    {Var name="lamp_state" loc="test.par"}
    {Var name="filter_pos"}
    {Var name="lamp_name"}
    {Var name="filter_name"}
    {Var name="retry"}