The variable definition option window is reached from the Define option that is available on several pop-up menus that provide help during the use of IFs.

IFs tries to avoid altogether the multiplicity of Greek and Latin letters that modelers often use in favor of 6-8 character variable names of the kind more common in computer code. Even these are, of course, difficult for a model user to remember or understand. Although such names continue to be used in the headers of tables or graphs and in some of the more flexible/detailed input and display mechanisms, IFs has steadily moved to primary input and display mechanisms that allow the user to call up information without knowing the variable names. When the shorter variable names continue to be used, the Define option can help the user understand them. It will produce a small window that normally has the short variable name and a longer and more descriptive one. It will also identify the scenario number and name of the result/run file to which it is attached.