What is the meaning / usage of IMAGE_DIRECTORY_ENTRY_LOAD_CONFIG?

In the Portable Executa开发者_开发百科ble format, there is a directory named IMAGE_DIRECTORY_ENTRY_LOAD_CONFIG. Can someone provide a URL with a good explanation of this directory and its real usage? Why do some apps use this feature?

It seems originally it was used for some rarely-used features (e.g. LockPrefixTable, I've only seen it in kernel32.dll). These days you generally only see it used for the /safeseh feature (SEHandlerTable/SEHandlerCount).