Information hiding technology embeds information using the redundancy of information contained in cover data. Therefore, many information-hiding techniques for cover data with a lot of redundancy, such as images or sound signals, have been proposed. Most proposed information hiding techniques that set document to cover data tampered with layouts between spacing and words. In this paper, a new information hiding technique for agglutinative languages like Japanese or Korean that have no spaces between morphemes is proposed. By the proposed technique, digital documents are set to cover data and secret data is embedded by making the position of the new-line code inserted into document correspond to secret data. The technique can also be applied to plain text like an e-mail, which does not have layout information. Because the technique does not change the content of the cover data at all, the technique can be used not only as steganography aiming at performing secret communication but also as digital watermarking. Moreover, the technique has the feature whereby embedded data remains also in the printing output.