+nature and the need of working in a chroot. Currently supported values: i386
+and amd64.
+
+ -b::
+
+Build the ISO without updating the chroot via FAI. This option is useful for
+example when working on stable releases: if you have a working base
+system/chroot and do not want to execute any further updates (via "-u" option)
+but intend to only build the ISO.