A dropfile is a simple binary or text file used by a bulletin board system

Bulletin board system

A Bulletin Board System, or BBS, is a computer system running software that allows users to connect and log in to the system using a terminal program. Once logged in, a user can perform functions such as uploading and downloading software and data, reading news and bulletins, and exchanging...

 (BBS) to pass information about the BBS itself and the current user to an external BBS door

BBS door

A door is a computer program, on a bulletin board system, that runs outside of the main bulletin board program. Sometimes called external programs, doors are the most common way to add games, utilities, and other extensions to BBSes. From the 1990s on, most BBS software had the capability to...

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Formats

Many different dropfile formats exist; most of these are application-specific. While there was never a "standard" dropfile, there were several formats that were commonly used. However, little documentation has survived for most of them. General formats are known, but specific values for certain fields or meanings for the actual fields have been lost with time.