What is the correct way to implement a 'party model' with the various roles that parties play?

Question

One of the programs we\'re working on is growing and we\'re at a stage where we can revisit the existing database and spend time \'trying to get it right\'. One of the things we

Answer 1

This SO answer has an implementation of parties.

Another answer, applying this pattern to articles and blog posts and stories has explanations of some of the subtle points in the comments.