mtrdesign

This plugin represents a RSS feed separator, which enables your readers to create RSS subscriptions that only contain posts with specific tags. 
For example, visitor A could create and subscribe to an RSS feed including the tags cooking, recipes, and fine living. Visitor B, could 
instead prefer to read posts related to the tags cocktails, wine, and night life. Each person will have it’s own RSS Feed URL, and each of 
those feeds will only include posts that have one or more of the preselected tags.
If you have a busy blog with lots of entries in it, you should definitely consider installing Selected Tags RSS, in order to enable your visitors 
to subscribe just to the topics they are interested in.
You can configure the location where the the RSS selector would be showing from the plugin settings. If your theme supports widgets you can add and configure a widget from Appearance > Widgets > Selected Tags RSS.
The plugin supports shortcodes. Use <code>[selected-tags-rss-post title="***"]</code> shortcode to show RSS link in posts and <code>[selected-tags-rss-search title="***"]</code> to show the RSS Selector. Title parameter is the optional name of link.
<a href="http://mtr-design.com/" rel="nofollow ugc">Plugin homepage</a>
Features:
<ul>
<li>A different Feed URL for each combination of tags</li>
<li>Simple administration interface</li>
</ul>
Take the time to read the user guide.
<h3>Usage</h3>
<h4>Adding the RSS Selector to the WordPress Sidebar</h4>
<ol>
<li>The plugin provides a widget called “Selected Tags RSS”. You can add this widget to your sidebar or other widget zone via Appearance > Widgets.</li>
</ol>
<h4>Adding the RSS Selector to a WordPress Page</h4>
<ol>
<li>Click on the “Selected Tags RSS” link in the WordPress administration menu to access the plugin settings.</li>
<li>Use the “Selected Pages” widget to Activate the RSS Selector for the desired pages by moving them from the left list to the right one.</li>
<li>Another option is to edit the page and use the shortcode following shortcode (title is optional): <code>[selected-tags-rss-search title="Generate RSS feed with these tags"]</code></li>
</ol>
<h4>Adding the RSS Link to WordPress Posts</h4>
<ol>
<li>The plugin provides a global setting called “Show RSS Link in Posts”, which is found at the “Selected Tags RSS” settings page in the WordPress administration menu. Enabling this setting will result in a special link being added to all Posts </li>
<li>Another option is to use the following shortcode in your Post (title is optional): <code>[selected-tags-rss-post title="Generate RSS feed with these tags"]</code></li>
<li>Yet another option is to edit your Posts template and call the function get_selected_tags_RSS(), as in: <code><?php echo get_selected_tags_RSS() ?></code>. </li>
<li>The automatically generated RSS Link text can be edited vie the plugin settings.</li>
</ol>

Selected Tags RSS

Enable separate RSS feeds covering different combinations of tags. Each feed will only list entries that match at least one of the feed's tags.

Tarmo Toikkanen

Adds tags, categories, and excerpts to pages. Also adds pages to most views 
that list posts, such as the main view, tag archives, and the rss feed.
The plugin has no settings, does not alter the database and only uses hooks 
to achieve its goal. It also should work perfectly fine with Multisite 
installations.

Pages are Posts

excerpts and they are included in post listings, including RSS/Atom feeds.

Selected Tags RSS vs Pages are Posts