Note that not all parts are required for all circuits. The title is used only to label the output. If you omit the title, and start only with a program statement it will be ignored by SPice. Usually, this will result in an aborted run. Comments are ignored by SPice except that they are included in the output file.
Comments are useful for making the program meaningful to other users.
The first step for describing a circuit in a SPice program is to number the circuit nodes. Of course, the number for different nodes must be different. The statements are written to describe the circuit. A separate statement appears for each circuit element. The first item in each statement is a name for the circuit element.