I was looking for a way to make a word unbreakable. The LaTeX User's Guide and reference Manual suggests using "\mbox{MYWORD}", but this will cause the now-unbroken MYWORD to hang off the edge of the paragraph. A similar behavior happens when using an intra-word "~": "M~Y~W~O~R~D" may stick out too far to the right of a paragraph, where I would expect it to be placed on the next line.