[Developers] magic null-or-empty-array?

[William Pietri]

My understanding is that a query that contains

    "*" : null

is magic in that null really means "please get me one value or many".


Is there a way I can do that myself for a specific query? E.g.,

    "varieties" : ???

where ??? is replaced with something that would return either

    "varieties":"Cirrus uncinus"

or

   "varieties":["Cumulonimbus incus","Cumulonimbus calvus"]

 
depending on which is appropriate?


Thanks,

William