parse.default(key, rest, srcref)parse.unknown(key, rest, srcref)
parse.value(key, rest, srcref)
parse.words(key, rest, srcref)
parse.name.description(key, rest, srcref)
parse.name(key, name, srcref)
parse.toggle(key, rest, srcref)
parse.default: emit value unchanged. parse.default: warns about unknown tag. parse.value: fail if empty parse.words: parse values into words separated by space parse.description: parse mandatory name and description parse.name: one and only one word parse.toggle: turn binary element on