In the first example, any request for http://server-name/whatever is translated to a request for http://tmpserver/whatever.
NameTrans fn="redirect" from="/" url-prefix="http://tmpserver/"
In the second example, any request for http://server-name/toopopular/whatever is translated to a request for http://bigger/better/stronger/morepopular/.
NameTrans fn="redirect" from="/toopopular" url="http://bigger/better/stronger/morepopular"