When a recipe is GET or PUT as JSON the following form is used:
{
    "recipe": [
        ["bag name 1", "select=tag:blog"],
        ["bag name 2", ""]
    ],
    "policy": {
        "read": [], 
        "write": [],
        "create": [],
        "delete": [],
        "manage": [],
        "owner": ''
    },
    "desc": "optional description of the bag (may be an empty string or absent)",
}