The sentence below often appears in a "blank" page of books. 

>"This Page Intentionally Left Blank"

Why there's no linking verb after the subject (**Page**)? e.g.:

>This Page **Was** Intentionally Left Blank

<br>

If the adverb in the original sentence is removed, we only have:
>This Page Left Blank

So I wonder why the original sentence without a linking verb often appears in books. Is it not odd without a linking verb? Based on my understanding of the original sentence, it means that the page left itself blank, which is odd for me.

Hope to get some clarifications about this.