Qs about rewrite syntax

biko

I am just getting into rewriting (part of a project at work I'm involved in) and have a httpd.conf file I've been looking at

A lot of the rules are written way before my time and the devs have moved to other companies. I've asked new devs about the syntax but they aren't sure so I thought I'd throw it up here in case someone will know better.
This is the first of a few conds/rules I am curious about:

RewriteCond %{HTTPS} (on)?
RewriteCond %{HTTP_HOST} ^example.com [NC]
RewriteRule ^/(.*) http(?%1s)://www.example.com/$1 [R=301,L]

The first cond turns off https but what is the bracketed (on) and question mark for? Should it not just be RewriteCond %{HTTPS} on
Also, the rule ^/(.*) is greedy and should capture example.com/justaboutanything

What is the (?%1s) used for?
$1 is filled from ^/(.*) yeah? And doesn't this mean a QSA is needed?

biko

Found info here
http://www.helicontech.com/forum/15029-ASPNET_40_MVC_and_ISAPI_Rewrite_3.html