+- **`<书社:archive>`:**
+ Each child element with a `@书社:archived-as` attribute will be
+ archived as a separate file in a resulting tarball (this attribute
+ gives the file name).
+ These elements will be processed the same as the root elements of any
+ other file (e·g, they will be wrapped; they can themselves specify
+ non X·M·L output types, ⁊·c).
+ Other child elements will be ignored.