Rewriting with .htaccess

Hi all

I'm trying to rewrite punbb forum thinking search engine optimisation.

I saw the .htaccess of the punBB 1.3 but they are some things that can be better for search engines.

For exemple, it have no interest to have an viewtopic-5.php url for ranking a webpage.
But an url like :
5-how-to-rewrite-punbb.html|php
is very pretty and useful for our friends the crawler.

I'll manage to rewrite all the forum but now i try to make better some details of the rewrite.
I hope i will can post all this stuff quickly here.

I need some informations to follow this work, it's the difference in viewtopic.php with the variable :
- $id
- $pid
- $pid=xxxx#pxxxx

For me, $id is the id of the topic.
$pid is the number of the post (join to topic i suppose in database)
$pid#p is the anchor of a post in topic where i fall directly in the number of the post ...(hmm ok ? )

Can you say me if that is correct ?

Very thanks for this stuff Rickards !