URLs in Microsoft Word documents by default appear as hyperlinks, and also don’t automatically break across lines. This is sometimes fine, but I think it looks bad in briefs and similar documents. The hyperlink is underlined and set in a different color, good if you want to click on it but otherwise distracting. And the line before often ends up having lots of white space, which is also distracting and unattractive.
Here’s how I solve these problems:
1. Turn the hyperlink into plain text by selecting it and then hitting ctrl-shift-F9. Alternatively, if you don’t want hyperlinks added by default at all, you can turn off that option in the Word AutoFormat-As-You-Type configuration.
2. Tell Word that it can break the hyperlink at a bunch of likely places (usually right after slashes or periods) using Insert / Symbol / Special Characters / No-Width Optional Break. If you find yourself doing this often, you can easily assign a shortcut key to this special nondisplaying symbol.
You can of course include an optional hyphen instead, but I think it’s generally not good for a word in a URL to be artificially hyphenated, since then a reader might think the hyphen is part of the URL. You can also enter manual line breaks, but that’s not optimal, because you don’t want the URL to break at a fixed place — you want it to break at the place that yields the least internal white space, and that might change as the earlier lines in the footnote change, or as the article gets reformatted.
The downside, of course, is that the URLs will no longer be clickable; but in my experience that feature is generally not important in briefs, while looking good and minimally distracting is important.