Bing supports the Robots Metatags detailed below. Each of these can also be emitted as X-Robots-Tag: in the response headers for the page. In all cases, you can replace the generic name="robots" with name="bingbot" or name="msnbot" to limit the meta tag to only apply to Bing. You can combine multiple values using a comma (e.g. "noindex,follow").
<meta name="robots" content="noindex">
Do not index the page. Use case: you want to keep a file that is crawled out of the Bing index. Note that we need to be able to crawl the page to see this tag, so do not block access to the page. By default we assume "index" but if needed you can use <meta name="robots" content="index"> to explicitly state that we may index the page.
<meta name="robots" content="nofollow">
Do not follow outlinks from the page. Use case: Prevent publicly writeable areas to be abused by spammers looking for link credit. By using NOFOLLOW, you let the robot know that you are discounting all outgoing links from this page. By default we assume "follow", but you can explicitly state "follow" if so desired.
<meta name="robots" content="noarchive">or
<meta name="robots" content="nocache">
Do not store a cached page for this document. Use case: you don't want to provide access to the indexed copy of the page in the search results cache.
<meta name="robots" content="noodp">
Do not use a description extracted from the Open Directory Project (http://dmoz.org)
<meta name="robots" content="nosnippet">
Do not show a description nor a preview thumbnail (were applicable) for the page.