Here is an example of how to create a problem data file, explained step by step:

Create and edit the file (problem_type_name.prb in this example) inside the problem_type_name directory (where all your problem type files are located). Except for the extension, the names of the file and the directory must be the same.
Start the file with the line:

PROBLEM DATA

Then add the following lines:

QUESTION: Unit_System#CB#(SI,CGS,User)
VALUE: SI
QUESTION: Title
VALUE: Default_title

The first question defines a combo style menu called Unit_System, which has the SI option selected by default. The second question defines a text field called Title, and its default value is Default_title.

To end the file, add the following line:

END PROBLEM DATA

The whole file is as follows:

PROBLEM DATA
QUESTION: Unit_System#CB#(SI,CGS,User)
VALUE: SI
QUESTION: Title
VALUE: Default_title
END PROBLEM DATA

The options defined in the .prb file can be managed in the Problem Data window (found in the Data menu) in the Preprocessing component of GiD.

Problem Data window in GiD Preprocessing

Browser not supported