Two things, one unrelated: The keys labeled Return and Enter on Mac keyboards are labeled Enter and Right Enter on Windows keyboards. So in a sense, Windows 2000 keyboards do lack a Return key, but they do have one with the same function.
And the other is related: Pressing Enter inserts a newline into the comment. But Slashdot comments are written in a subset of HTML, and one of Slashdot's post modes does not convert newlines into HTML line break elements. Furthermore, the modes have misleading names:
- "HTML Formatted": Do no translation at all apart from sanitization.
- "Plain Old Text": Translate line breaks and allow inline HTML, like PHP nl2br($post).
- "Extrans": Translate line breaks and escape all < signs, like PHP nl2br(htmlspecialchars($post)).
- "Code": Translate line breaks, escape < signs, and use monospace formatting, like PHP '<pre>'.htmlspecialchars($post).'</pre>'.