1. Introduction

1. Introduction

In many applications, it is possible for a user to be presented with a form. The user will fill out the form, including information that is typed, generated by user input, or included from files that the user has selected. When the form is filled out, the data from the form is sent from the user to the receiving application.

The definition of multipart/form-data is derived from one of those applications, originally set out in [RFC1867] and subsequently incorporated into HTML 3.2 [W3C.REC-html32-19970114], where forms are expressed in HTML, and the form data is sent via HTTP or electronic mail. This representation is widely implemented in numerous web browsers and web servers.

However, multipart/form-data is also used for forms that are presented using representations other than HTML (spreadsheets, PDF, etc.) and for transport using means other than electronic mail or HTTP; it is used in distributed applications that do not involve forms at all or do not have users filling out the form. For this reason, this document defines a general syntax and semantics independent of the application for which it is used, with specific rules for web applications noted in context.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14, RFC 2119 [RFC2119].