inc/class-Inform_About_Content.php
public function append_signature( $message, $signature = '' ) {

		if ( empty( $signature ) ) {
			return $message;
		}

		$separator = apply_filters( 'iac_signature_separator', str_repeat( PHP_EOL, 2 ) . '--' . PHP_EOL );

		return $message . $separator . $signature;
	}
public function append_signature( $message, $signature = '' ) {

		if ( empty( $signature ) ) {
			return $message;
		}

		$separator = apply_filters( 'iac_signature_separator', str_repeat( PHP_EOL, 2 ) . '--' . PHP_EOL );

		return $message . $separator . $signature;
	}
apply a signature-text to the email message

@since 0.0.6 (2013.01.13)

@param string $message ,
@param string $signature (Optional)

@return string