RSS parameters and custom content

I've got a little stuck here. My boss has asked me to look into the possibilities of RSS feeds, to use them to show updates of a website. If it was just how to create a simple RSS feed, I would have done it already, no trouble there.

But, he wants some more specific functionalities, as I've so far have had a hard time finding any usable instructions for implementation; like being able to give the RSS XML document parameters and thereby make them "generate" only relevant content. Specific content generated using parameters like username (for identification probably) and what's new since last time (like, last time the feed was read by this specific user).

The problem is, I don't know (and can't find) if there's an accepted "standard" way of doing this kind of parameter magic, and if there's any resources about it out there.

Just like:

www.domain.com/rss/feed.xml?username=JSKDJL&since=[unix timestamp or the like]

Thus, I can't help but thinking, that stupid XML documents like RSS cannot do dynamic stuff, and the parameter handling should therefore be handled by some server script. Like PHP that responded to files with .xml extension?

So, what I basically need to know (and trust me guys, I've searched for this already):

• Resources of what is commonly accepted parameters to be given to RSS documents (if any)
• How is it/should it be implemented? Server script? Any known libraries and the like that can do this already?
• How would RSS r开发者_StackOverflow中文版eader services like the one of Google's fit into this? Would there be problems?

An RSS XML document in itself does not contain any logic.

You need to generate the appropriate feed for the parameters with some server side logic, like a PHP script or the like.

And there are no standard parameters, just make something up that would suit you.

For perl, i've used XML::RSS with success.