For position only
In graphic design and printing, FPO (pronounced as an initialism) equates to for position only or for placement only. Blank placeholders or temporary low-resolution illustrations are watermarked or stamped with the acronym FPO to indicate where the final version of an image is to be placed in the final file, film, or plate. FPO images are commonly used while the layout of a print project is being determined, and/or when desired images are still to be scanned or photographed. They preserve the pagination that will be needed once the final images are added. In web design, FPO placeholder images provide a means for coders to finish building a website without waiting for final photographic assets.
The purpose of stamping or watermarking "FPO" prominently over the image is to prevent the low-res image from being mistakenly kept in the final output. It also prevents the accidental inclusion of copyrighted images if the designers used an image whose use for which they do not have the rights as a placeholder. The watermark makes the image's not-final status egregiously obvious, whereas without the mark it would be subtler and easier to miss. This reduces the risk that production staff will forget to replace it with the final image. Rarely, an FPO image makes it into print, usually because the production staff was overly rushed.