For, begin, and end will let you have regions of text/code/data
that are not generally interpreted as normal POD text, but are
passed directly to particular formatters, or are otherwise special.
A formatter that can use that format will use the region, otherwise
it will be completely ignored.

##</code><code>##

=begin markdown

# PARAMETERS

The following are good parameters:

* **-foo**
...

=end markdown