The following code

{RSS(id=>3)}{RSS}

produces:

The following code

{RSS(id=>2)}{RSS}

produces:

And the following code

{RSS(id=>2+3)}{RSS}

should combine the 2 RSS feeds, but as of 2007-06-12 (BRANCH-1-9), it does not.

FIX: The reason why this is so is because if you are combining feeds, "show publish date" must be checked in the RSS module settings, in order to allow this plugin to sort the combined feeds. all fixed for 1.9.8