linux security - Jan 1999 - ipfwadm and filtering ICMP?

I would like to allow certain types of ICMP traffic and not others.
Is there a way, with ipfwadm do this?  I currently either can deny
access to ICMP for what I want or allow it.  

Any good examples out there?

[mod: Please summarize in about a week, OK? -- REW]

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Peter Kelly
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