[!--quoteo(post=385090:date=Jun 17 2006, 08:52 PM:name=steelmanronald06)--][div class=\'quotetop\']QUOTE(steelmanronald06 @ Jun 17 2006, 08:52 PM)
Regular Expressions (RegEx).
This is simple to understand. The rule works like this. A url that someone types in like so:
[a href=\"http://www.site.com/listing/700\" target=\"_blank\"]http://www.site.com/listing/700[/a]
will actually point to:
[a href=\"http://www.site.com/listing.php?type=$1\" target=\"_blank\"]http://www.site.com/listing.php?type=$1[/a]
The best part about it is it is Spider Friendly, easy to remember, and when a user points to the first url they will always see it but the webserver will see the second url.
Sorry I should have made it clearer, I know the point and theory behind mod rewrite, i just dont understand the rules, are you saying they use regular expressions? I will check on that in any case. The $1 actually gets converted to some value given by the url. This is what is confusing me.