adding a note [custom description?] to a EACH post in a category

Sorry if this is entirely confusing or already asked and answered, but I can't think of how to express my question any better.

1) I'm building a WP/GP Themed site, where selected twitter posts, are auto fed to it and listed under a particular category as posts.

2) I want to add a standard "custom description" to each of these auto posts, in this particular CATEGORY, simply stating the content is not my intellectual property and appears in good faith, for information only etc

Any tips please, on how can I set this up, so it does it automatically, to EACH post please?

Thank you for any help offered.