iRule Script request

Is there any specific condition that has to be met for this redirect to happen? Is it a specific URI?

if { [string tolower [HTTP::uri]] starts_with "/level1/level2/level3.aspx" } { ...

Is it a specific host name?

if { [string tolower [HTTP::host]] equals "bbb.aaa.com" } { ...

Or do you simply redirect all traffic from an HTTPS site to an HTTP site?

when HTTP_REQUEST {
    HTTP::redirect "http://[HTTP::host][HTTP::uri]"
}