This group of commands can be used to create your own document class or package by building on existing classes or packages.
\RequirePackage [<options-list>] {<package-name>}
[<release-info>]
\RequirePackageWithOptions {<package-name>}
[<release-info>]
Packages and classes should use these commands to load other packages.
The use of \RequirePackage is the same as the author command
\usepackage.
Examples:
\RequirePackage{ifthen}[1994/06/01]
\RequirePackageWithOptions{graphics}[1995/12/01]
\LoadClass [<options-list>] {<class-name>}
[<release-info>]
\LoadClassWithOptions {<class-name>}
[<release-info>]
These commands are for use only in class files, they cannot be
used in packages files;
they can be used at most once within a class file.
The use of\LoadClass is the same as
the use of \documentclass to load a class file.
Examples:
\LoadClass{article}[1994/06/01]
\LoadClassWithOptions{article}[1995/12/01]
The two WithOptions versions simply load the class (or package) file
with exactly those options that are being used by the current file
(class or package). See below, in 4.5, for further
discussion of their use.