How to write a list of citations
The aim of the document is to have a verifiable version of your citation count, which is commonly used for filtering out some applicants in an application process. It should provide a list of your papers together with their citation counts, and it needs to back this up by data (such that it is verifiable). This means listing for each of your papers which other paper cites it.

There seems to be only one reasonable way to structure such a document, to  first list all of your papers with the citation counts, and to then use seperate sections for each of your papers with the biliography entries for the papers citing your paper. In this way, you give the information that is mainly useful for verifying your citation count later in the document, while giving the important information first. 

I doubt that there is any "official" information on how to format such a document. After all, scientists know that citation counts are a bad way to evaluate a researcher's output. So there is no urge to stress the importance of these documents by providing additional formatting requirements.