29 CFR §4003.34

1. (a)Be in writing;
2. (b)Be clearly designated as a request for reconsideration;
3. (c)Specifically explain why PBGC's determination is wrong and the result the requestor is seeking;
4. (d)Describe the relevant information the requestor believes is known by PBGC and summarize any other information that is relevant to the request for reconsideration; and
5. (e)Include copies of any documentation that supports the requestor's claim or assertions.