1. A method of communicating a modular document from a first electronic device to a second electronic device, comprising: determining, by the first electronic device, which one or more component documents of the modular document are already available at the second electronic device, wherein the modular document is composed of plural component documents; and creating, by the first electronic device, a package that includes the modular document and a subset of the plural component documents of the modular document, wherein the subset of the plural component documents is other than the one or more component documents already available at the second electronic device, wherein the modular document in the package includes references to the plural component documents, and wherein the first electronic device does not include in the package the one or more component documents determined by the first electronic device to be already available at the second electronic device; and sending, by the first electronic device to the second electronic device, the package.
1. A method of communicating a modular document from a first electronic device to a second electronic device, comprising: determining, by the first electronic device, which one or more component documents of the modular document are already available at the second electronic device, wherein the modular document is composed of plural component documents; and creating, by the first electronic device, a package that includes the modular document and a subset of the plural component documents of the modular document, wherein the subset of the plural component documents is other than the one or more component documents already available at the second electronic device, wherein the modular document in the package includes references to the plural component documents, and wherein the first electronic device does not include in the package the one or more component documents determined by the first electronic device to be already available at the second electronic device; and sending, by the first electronic device to the second electronic device, the package. 9. The method of claim 1 , further comprising: identifying references in the modular document to included documents and at least one reference to an opportunistically included document, wherein the subset includes one or more of the included documents; and deciding whether or not to add the opportunistically included document into the subset based on a policy at the first electronic device.