While reading this topic about software skills in resume's I remembered a discussion I have been having with myself for quite some time.
In many resumé's, including those I received from prospective new colleagues I often see that the specific skills are rated or been given a note. For instance PHP 9 out of 10.
What method of listing skills is more professional and gives the proper understanding of what you can and cannot do? For instance I think that describing projects and tagging them with skills accordingly is a very good way to interpret experience. Alternatively I like the idea of going into depth about the exact specifics of one abstract skill (cloud hosting for instance) by mentioning more information per skill based on experience.
Without making this question marked for closure due to being too subjective or too wide, the exact question: What added value does rating your skills have in comparison to not rating them?