Source

File: wp-includes/class-wp-rewrite.php

public function iis7_url_rewrite_rules( $add_parent_tags = false ) {
		if ( ! $this->using_permalinks() ) {
			return '';
		}
		$rules = '';
		if ( $add_parent_tags ) {
			$rules .= '<configuration>
	<system.webServer>
		<rewrite>
			<rules>';
		}

		$rules .= '
			<rule name="WordPress: ' . esc_attr( home_url() ) . '" patternSyntax="Wildcard">
				<match url="*" />
					<conditions>
						<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
						<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
					</conditions>
				<action type="Rewrite" url="index.php" />
			</rule>';

		if ( $add_parent_tags ) {
			$rules .= '
			</rules>
		</rewrite>
	</system.webServer>
</configuration>';
		}

		/**
		 * Filters the list of rewrite rules formatted for output to a web.config.
		 *
		 * @since 2.8.0
		 *
		 * @param string $rules Rewrite rules formatted for IIS web.config.
		 */
		return apply_filters( 'iis7_url_rewrite_rules', $rules );
	}