MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)

HTML [RFC 1866] defines a powerful means of specifying multimedia documents. These multimedia documents consist of a text/html root resource (object)and other subsidiary resources (image, video clip, applet, etc. objects) referenced by Uniform Resource Identifiers (URIs) within the text/html root resource. When an HTML multimedia document is retrieved by a browser, each of these component resources is individually retrieved in real time from a location, and using a protocol, specified by each URI. In order to transfer a complete HTML multimedia document in a single email message, it is necessary to:a) aggregate a text/html root resource and all of the subsidiary resources it references into a single composite message structure, and b) define a means by which URIs in the text/html root can reference subsidiary resources within that composite message structure. This document does both. It a) defines the use of a MIME multipart/related structure to aggregate a text/html root resource and the subsidiary resources it references, and b) specifies two MIME content-headers (Content-Base and Content-Location) that allow URIs in a multipart/related text/html root body part to reference subsidiary resources in other body parts of the same multipart/related structure. While initially designed to support e-mail transfer of complete multiresource HTML multimedia documents, these conventions can also be employed by other transfer protocols such as HTTP and FTP to retrieve a complete multi-resource HTML multimedia document in a single transfer or for storage and archiving of complete HTML-documents. Differences between this and a previous version of this standard, which was published as RFC 2110, are summarized in chapter 13.