Mock question

[Eric Tanguy <eric tanguy univ-nantes fr>]

I have a fc4 box. Is it possible with a special configuration to try to
build a package against the devel version ?

I see in /etc/mock : 
default.cfg                         fedora-5-i386-core.cfg
fedora-3-i386-core.cfg              fedora-5-ppc-core.cfg
fedora-3-x86_64-core.cfg            fedora-5-x86_64-core.cfg
fedora-4-i386-core.cfg              fedora-development-i386-core.cfg
fedora-4-i386-core.cfg~             fedora-development-ppc-core.cfg
fedora-4-ppc-core.cfg               fedora-development-x86_64-core.cfg
fedora-4-x86_64-core.cfg
why there is fedora-5 and fedora-development

Eric