<note> <p>This is <b>AWS WAF Classic</b> documentation. For more information, see <a href="https://docs.aws.amazon.com/waf/latest/developerguide/classic-waf-chapter.html">AWS WAF Classic</a> in the developer guide.</p> <p> <b>For the latest version of AWS WAF</b>, use the AWS WAFV2 API and see the <a href="https://docs.aws.amazon.com/waf/latest/developerguide/waf-chapter.html">AWS WAF Developer Guide</a>. With the latest version, AWS WAF has a single set of endpoints for regional and global use. </p> </note> <p>Inserts or deletes <code>RegexPatternString</code> objects in a <a>RegexPatternSet</a>. For each <code>RegexPatternString</code> object, you specify the following values: </p> <ul> <li> <p>Whether to insert or delete the <code>RegexPatternString</code>.</p> </li> <li> <p>The regular expression pattern that you want to insert or delete. For more information, see <a>RegexPatternSet</a>. </p> </li> </ul> <p> For example, you can create a <code>RegexPatternString</code> such as <code>B[a@]dB[o0]t</code>. AWS WAF will match this <code>RegexPatternString</code> to:</p> <ul> <li> <p>BadBot</p> </li> <li> <p>BadB0t</p> </li> <li> <p>B@dBot</p> </li> <li> <p>B@dB0t</p> </li> </ul> <p>To create and configure a <code>RegexPatternSet</code>, perform the following steps:</p> <ol> <li> <p>Create a <code>RegexPatternSet.</code> For more information, see <a>CreateRegexPatternSet</a>.</p> </li> <li> <p>Use <a>GetChangeToken</a> to get the change token that you provide in the <code>ChangeToken</code> parameter of an <code>UpdateRegexPatternSet</code> request.</p> </li> <li> <p>Submit an <code>UpdateRegexPatternSet</code> request to specify the regular expression pattern that you want AWS WAF to watch for.</p> </li> </ol> <p>For more information about how to use the AWS WAF API to allow or block HTTP requests, see the <a href="https://docs.aws.amazon.com/waf/latest/developerguide/">AWS WAF Developer Guide</a>.</p>