Found the answer myself, reviewing php files smile
Right id topic argument is: $id

So, valid php code:

if ($pun_config['o_announcement'] == '1' && $id == '22' || $id == '27')

Hello, I want show announcement only in /viewtopic.php?id=22 and /viewtopic.php?id=27.

I should edit header.php, add:

if ($pun_config['o_announcement'] == '1' && [VALID_PHP_CODE]== '22' && [VALID_PHP_CODE]== '27')


[VALID_PHP_CODE] = I tried all the options that I know nothing works.... sad

*PunBB 1.2.15

Thank you very much!