The NIL/PIL coding guidelines are a set of rules that should be followed by all lab members. The purpose of the guidelines is to help members produce code that is, to some degree, standardized. The benefits for maintaining, reusing, and generally sharing code between members are obvious.
These rules apply specifically to C source code, but most of them can be readily adapted to FORTRAN or other languages. The rules are divided into three sections: requirements, strong suggestions, and suggestions. The requirements must be followed by everyone. The strong suggestions usually include reasons why you would and would not want to follow them. The suggestions are usually more controversial, and although possibly good ideas, may be followed at your discretion.