wcm_global_context vs new_wcm_context

[Joey Chen]

Does anyone know when are the appropriate uses for these two?

When would I link to a content item using:

http://[PORTAL_HOST]/[PORTAL_CONTEXT_ROOT]
/[PORTAL_PAGE_URL_MAPPING]/?New_WCM_Context=[ILWWCM_PAGE_URL]

vs

http://[PORTAL_HOST]/[PORTAL_CONTEXT_ROOT]
/[PORTAL_PAGE_URL_MAPPING]/?WCM_GLOBAL_CONTEXT=[ILWWCM_PAGE_URL]

Thanks,