All data between specified begin and end tag pairs will be stripped
from the HTML before the text is extracted (i.e. links are
unaffected). These are simple strings, not patterns nor REX
expressions, and the case is ignored. This is useful for excluding
boilerplate or otherwise unwanted portions of HTML documents. Tag
pairs should not nest nor overlap in documents. Documents with no
begin tag will be unaffected. Documents with no end tag after the
last begin tag will still discard HTML from the last begin tag to end
of document.
