You can use all Help+Manual's global predefined variables and your own user-defined variables in the text objects in PDF print manual templates. In addition to this there are also a number of special predefined variables that can only be used in print manual templates. These variables are described and listed in the separate help and documentation of the Print Manual Designer program included with Help+Manual.
Conditions are not supported in PDF print manual templates. You cannot use conditional text or any other conditions in these templates.
Just type the variable in any text object in your PDF template, using the standard <%VARIABLENAME%> syntax.
These variables can be typed in manually but they can also be inserted from a list by selecting the Variable button in the text object dialog. This option is preferable because it automatically shows you which PDF template variables are valid in the current location.