The paper introduces a more concise, more accurate description of Google's PageRank algorithm than has previously been published in the SEO community. New concept defintions include:

Delisting - This is the most radical action. A document is completely removed from the searchable index and won't even come up for its own title tag or URL.

Penalization - A document appears in the index but won't rank well for any search expressions except the most obscure. You usually have to find the document by URL.

Devaluation - A document appears in the index and may even rank well on the basis of its own factors. But none of its outbound links confer PageRank or reputation. The links may still be crawled, but Matt has not indicated whether this is so.

Scope Reduction - Having done nothing wrong, a document suddenly loses position or all ranking for one or more (but not all) of its targeted search expressions.

Rank Loss - Having done nothing wrong, a document suddenly loses significant position within the search results.

Rank Depression - Having done nothing wrong, a document suddenly loses all position within the search results. It suffers as if it has been Penalized for no apparent reason.

This paper looks at a number of comments by Google engineer Matt Cutts and places them in a context that is relevant and important to anyone interested in advancing their skill in Google optimization.

Read the full paper here:
Google Reputation and Trusted Content