They may appear in integer, real, or scientific notation. Also, TSP scalars may be used. Note that, logically, a certain number of observations are lost in generating a lagged variable. See the complete TSP manual. The LIST instruction is used to refer to a list of TSP variables as a group, by defining a listname that can be referenced by other instructions.
Printing operates under SMPL control.
It is usually a good idea to print out the data for variables to be used in a regression, especially if variables were generated. Comments are terminated at the end of the line.