Bug#413257: installation-guide: '&debian-mirror;' in example-preseed.txt
is this line
d-i mirror/http/hostname string &archive-mirror;
That seems to me a mistake in the build process of the manual,
where the XML entity '&archive-mirror;' should have been replaced
with 'ftp.nl.debian.org' or another hostname.
If it is not a build error, then is the fix is much easier,
but an archive host has to be decided...