Question on P4 proc and chipsets

I’m confused about people saying that a faster (or newer) P4 proc won’t work with older chipsets. Like if I buy a P4 with 800mhz FSB it won’t work with a chipset rated for 400mh FSB. My understanding is that FSB are just a rating and if put faster p4 on older chipset, it will just slow down…am i right?

I’ll appreciate if anybody can provide a link about p4 procs and chipset compatibilit.

Its backwards compatinble. 99% of boards will clock it down.
You will just not be using the chip to full potential. Some boards may see it as overclocked possible becase of the higher multiplier, but like I said before justa bout all boards now can auto-detect and adjust.