#### 36.4.2 The INDEX file

The optional `INDEX` file provides an categorical view of the functions in the package. This file has a very simple format

- Lines beginning with `#` are comments.
- The first non-comment line should look like this

                toolbox >> Toolbox name

- Lines beginning with an alphabetical character indicates a new category of functions.
- Lines starting with a white space character indicate that the function names on the line belong to last mentioned category.

The format can be summarized with the following example

         # A comment
         toolbox >> Toolbox name
         Category Name 1
          function1 function2 function3
          function4
         Category Name 2
          function2 function5