setting default content with links+howto
To specify default content, you add one or more key/value pairs at the end of a link to create a new card. Each key specifies a compound names you want to put default content into, and each value is the default content that goes into that plus card. So http://www.wagn.org/new/Recipe?_serves=1 offers to create a Recipe card, with it's "+serves" card filled out with 1. Note that the name of the plus card has an underscore before it (this is to distinguish these from other keys Wagn uses in URLs — see web address for everything).
The type of the card being created must have been formatted with that plus card on it. I.e., in this case, "Recipe+*type+*content" must contain {{+serves}}.
Additional plus cards can be given default values by simply adding parameters: