Unique field | drupal.org

This module performs additional validation when a node is created or updated by a user to require that a node's title, author, language, and CCK fields are unique within a given context.

All those are configurable options.

Search words:
drupal prevent duplicate submissions
drupal prevent duplicate node titles
drupal deny duplicate content

I was getting all excited about writing this module when I finally found it, at the last second, while brainstorming titles for it. (No, unique field

http://drupal.org/project/unique_field

This was the thread that finally led to this useful module:

deny duplicate node titles
http://drupal.org/node/89599

Some 4.7 era code, a bit more ambitious than I am going for
Dupe-R-Scooper: prevent duplicate content
http://drupal.org/node/182860

Ted Serbinski solves a similar problem (in Drupal 5) in a way that is straightforwardly adaptable to our use case.

http://tedserbinski.com/2007/06/04/preventing-duplicate-posts-part-2

The problem Ted is trying to solve is doubling or more the submissions.

http://drupal.org/project/formsingle
http://drupal.org/project/hide_submit

Is this person more looking for my kind of solution?
"Submit Once - preventing duplicate nodes (and even comments)"
http://drupal.org/node/162048