Code quality testing detects poor operating code and violations of W3C or IETF standards, which may affect the visual display of your web site or slow it down.
Code quality tests check that the HTML sent to visitors conforms to standards. For example, checking tags have been closed correctly.
Walkthrough of the Code Category
Code / HTML
The Code Quality summary provides a management overview of the Code Quality category showing the current score, a chart of performance over time and the number of priority, secondary and tertiary actions.
There is the ability to email the Priority Actions, e.g. to the people responsible for fixing them.
The top issues are also identified, and these are shown together with the number of occurrences of each issue. Issues that have a very large occurrence are likely to be with templates. Fixing a template will likely have a big improvement for the entire site.
You can drill down further into each issue and use SMARTVIEW to see where the issue occurs on the page and also see it highlighted in the source code.