is there a standard way to get the g-b-s to apply multiple patches?

[Yitzchak Scott-Thoennes]

I'm working on updating the fortune package and switching to use the
generic build script, but I'd like to have the source package to have
the original source, the current debian patches, and a separate patch
file with my patches.  The debian package maintainer is also the
maintainer of the upstream source, but he isn't updating that, just
letting the debian patches get bigger and bigger over time.  I'd like
my patches to be distinguishable from what's standard.