Help contexts are added by using the org.eclipse.help.contexts extension point. Contexts are usually specified by using a separate help plug-in, making it easier to switch help content for various languages. The context extension specifies the path of a separate XML file where the data is stored:
<extension point="org.eclipse.help.contexts">
<contexts
file="help_contexts.xml"
plugin="org.eclipse.faq.examples">
</contexts>
</extension>
The contexts file includes a description for each context and can, optionally, add links to HTML help content files in the plug-in. See the help documentation for more details on the format of help context files.
Go to Platform Plug-in Developer Guide > Programmer's Guide > Plugging in help**.**