NSF_DUMP is a handy tool that displays the contents of a Notes database file — and it does this in a format designed to help you figure out how that information got stored there in the first place. Armed with this understanding, you can use the Notes C API to programmatically read data stored in any Notes database file and recreate, or reverse engineer, just about any object stored there: plain text, rich text, form designs, view designs, agents, navigators, and so on. This article demonstrates how to use NSF_DUMP to learn how a collapsible section is stored in Notes and then how to use the Notes C API to create a note that contains a collapsible section. This simple exercise can be used as the foundation for reverse engineering more involved applications