How about if we allow for an optional ID, that would be unique to the
individual program. Then if a recipe calls for other recipes as
ingredients, they can refer to those recipes' IDs. If a user chooses
to export such a recipe, the software could give them the option to
export just the recipe, or to also include the other recipes in the
export. Then when the user imports a file that has several connected
recipes in it, the software can handle those ID's how it wants,
including renumbering the ID's to its own scheme if necessary.
Much of this would be a function of the software, but I'm thinking
that this kind of support would be useful.
--
Joseph