Selecting the right pattern for adding in robots.txt I've some views with exposed filters but I find that Googlebot is indexing them. In short I don't want any of those Views content by generated exposed filters to be seen by Google.

This page has listed more about it.

I want a pattern which should work for almost all views by restricting access to content generated by changing exposed filters.

Will this cause any issues?:

Disallow:/*&amp;sort_order=*


Assuming we always specify sort order in Views. Is there any other module(s) which may generate url containing this parameter?
Adding the line you suggest to you site's robots.txt will stop googlebot from crawling the URLs that contain this string.

However, what attributes modules add to the URL is up to the module.  You need to examine the source code of the modules you use to avoid any conflict. I doubt there is anyone here with encyclopedic knowledge of what attributes every module use (there are more than 20000 on Drupal.org).

Instead of searching through modules for possible conflicts, I would invent a "magic" string that is pretty much guaranteed to be unique or not used for any other purpose by a Drupal module (e.g. "dontcrawlme") and add that "magic" string to the path to the views I don't want crawled, or add a dummy attribute with "magic" string as name to those views, then Disallow any crawling of an URL containing the "magic" string. This is simpler and more robust than relying on sort_order= being unique for exposed filters in Views.

You need to take care not to overwrite your custom additions to robots.txt when you do a minor upgrade of the Drupal core.

Note that wildcards is not part of the Robot Exclusion Standards (but are supported by googlebot and bing), so don't expect any rule with wildcards to be widely recognised by robots.