Manage URLs with multiple parameters

A single URL can contain many URL parameters and you can specify crawling settings for each one. Keep in mind that Google takes the following approach when dealing with multiple URL parameters:
The more restrictive URL parameter crawling settings override the less restrictive settings.
For example, below are three URL parameters and their respective Google crawling settings as set with the URL Parameterstool:

Parameter	Parameter crawl settings
shopping-category	Crawl all URLs with this parameter.
sort-order	Crawl only URLs with value = production-year.
sort-by	Crawl only URLs with value = asc.

Based on the above settings, Google can crawl the following URL because the URL Parameters page allows Google to crawl only URLs with the production-year and asc parameters values:
Example URL 1: http://www.example.com?shopping-category=DVD-movies&sort-by=production-year&sort-order=asc.
However, Google would not crawl the next URL because, although the URL contains a valid shopping-category parameter value, shoes, and the sort-order parameter is asc, Google can’t crawl a URL where the sort-by parameter is not set to production-year:
Example URL 2: http://www.example.com?shopping-category=shoes&sort-by=size&sort-order=asc.
The above example showcases why it’s important to carefully consider the crawling settings you assign to certain URL parameters. The second URL with the shopping-category parameter is a web page that displays a collection of shoes. Since shoes aren’t typically sorted by production year, the restrictive setting sort-by=production-year prevents all shoe pages from being crawled by Google.