Wildcards are used for matching entire groups of similar URLs. For example, suppose you only want to show the Drip widget on the /blog subdirectory of your site. To achieve this, you need to use a wildcard
Here's an example:
Single & Double Wildcards
There are two kinds of wildcards: a single asterisk(*), and a double asterisk(**). The single asterisk matches an individual URL segment. For example, "/register/*" matches "/register/basic but does not match /register/basic/123" and so on.
The double asterisk(**) wildcard matches one or more URL segments. For example, "/blog/**" matches "/blog/123 and /blog/category/marketing/1234" and so on.
Here are a few examples of how to mix wildcards together:
/**/comments/* matches /abc/xyz/comments/23
/**/category/**/show matches /blog/archive/category/1/2/show
You can also use the single asterisk(*) wildcard in the query string. For example, /blog/**?s=* will match any page under the blog subdirectory with the query string parameter set to anything.