1) Put it in a stomach acid-resistant capsule, close it, and then swallow it.
2) Stick it to a piece of foil and freeze it in an ice cube tray.
3) Put it in the revers of a jacket hanging in the wardrobe with other jackets.
4) Put several papers together with several paper clips in a file folder and place the folder with the other folders.
5) Attach a photo with a sticky note clip it with the paper clip, and then pin it clearly visible to an information board.