Provides the framework for explicitly providing an entire "SGML document entity" to the SGML parser and is used to control where input comes from in a down-translation.
#documentcannot be mixed with entity names or with
#syntaxin the header of the rule (for example,
external-text-entity #document | #dtdis not allowed).
external-text-entity #documentrules in the program, one, and only one, must be selected to provide the SGML document entity. (An error will be issued if none or more than one is selected.)
external-text-entity #documentrule must not contain any
find-endrules (there is no reason for them to be performed).
external-text-entity #documentrule only applies to the main SGML document, and not to documents whose parsing was initiated by a
do sgml-parse. Thus, the
#current-outputinherited by an
external-text-entity #documentrule is always the
#sgmlstream created by the
external-text-entity #documentbecause this type of text entity does not have a name.