Clientupdate minimum version 🔗 link

Hello,

I couldn't find any documentation regarding this, but is there a
minimum version for the clientupdate to work properly?  I have just
upgraded my server to the RC for 4.2, but I am still using the
BigBrother client and deploying the client to my servers step by step,
and would prefer not to have to deploy clients again once a "stable"
version is released.

Thanks,

Jeffrey Chandler