Google introduced parameter handling last year to help SEOs manage duplicate content (e.g., session IDs, source, language). Parameter handling allows SEOs to view which parameters Google thinks should be ignored or not at crawl time, and to overwrite Google's suggestions.
On Friday, Google announced that webmasters now have the ability to choose a specific value among the known values for a given URL parameter.
This is important when a parameter is relevant to the content, but different values of this parameter lead to similar pages. For example, consider a sorting parameter, like "sort-by" in the following URLs:
These four URLs show products in the candy category. There are enough items in this category to fill two pages, and the products shown can be sorted by price, in ascending or descending order. Selecting action "Ignore" for parameter "sort-by" would be incorrect and could potentially limit our indexing of the site. This is because, after ignoring "sort-by", we would consider the first two URLs equivalent and may choose to index the URL with ascending sort order. We would also consider the last two URLs equivalent and may choose to index the URL with descending sort order. In this scenario, we would be indexing the candy category inconsistently, with some candy products appearing in both of the pages selected for the index, while other candy products not appearing in either of them. The right solution comes from the new action "Use specific value" now available in Webmaster Tools. To avoid duplicates but still keep our indexing consistent, you can simply select action "Use specific value" for parameter "sort-by" and choose one of the valid values, say "asc-price". After this, our indexing would be fully consistent, as we would focus only on the pages with products sorted by ascending price.
Google also announced that they're making it easier to identify search query trends by adding a "change" column next to the impressions, clicks, CTR, and averageposition columns.
To help you find messages quickly, you can also now add a star to specific messages, and a separate "Starred" view where you can find all your starred messages.