Nodewords lets you add meta tags to nodes for abstract, copyright, description, keywords, revisit-after, and robots.

Download Nodewords from drupal.org/project/nodewords. There are permission controls to limit access by role and meta tag type. You could have one role allowed to add only abstract while another role can add abstract plus copyright.

Nodewords contains the following modules. you need at least Nodewords and Nodewords - basic meta tags.
Nodewords Allows users to add meta tags, e.g. keywords or description. This module doesn't actually implement any meta tags, but requires other modules to implement them.
Nodewords - basic meta tags Allows users to add basic meta tags to Drupal pages. Depends on: Nodewords.
Nodewords - extra meta tags Allows users to add extra meta tags to Drupal pages. Depends on: Nodewords.
Nodewords - site verification meta tags Allows users to add site verification meta tags required by some web sites (mainly from search engines). Depends on: Nodewords.