MIC provides a global hash, that is reset for each call to a MIC page,
which may be referenced from any page code (but not fieldspace code
unless passed in by some mechanism) called `headers.' The keys of this
hash are intended to be header lines and the values their values. They
will be printed as <
key>
= ``<
value>
''.
This hash is normally not accessible from the fieldspace because the fieldspace code gets compiled into a different package.