Definitions for True and False for presentation:placeholder

19.411 presentation:placeholder reads:

The presentation:placeholder attribute specifies if a shape is a placeholder or a presentation object with content.

It has a Boolean data type but here's the kicker: No definition of the operation of true or false.
So, what's the word on:

true -
false -

??

One says the shape is a placeholder and the other, a presentation object with content.