Sketching and wireframing are a specialized style of drawing, used for fleshing out preliminary complex ideas, group brain-storming, a lo-fi method for evaluating interaction concepts, and as a way of roughly perfecting a design technique.
Sketch and wireframe paper is essentially drawing paper that is designed specifically for this purpose. You could use it for web page design, web app design, architectural or structural design, graphic design, movie direction, animation... basically any type of design that needs a physical creative outlet or group collaboration.
Not all sketch and wireframe sheets are universal, most are specialized for a particular medium, such as storyboards and specialized grid paper (axonometric perspective templates).
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.