What does the second tick mean in Telegram group-chats? Telegrams FAQ only explain what the green ticks mean in a normal chat ( https://telegram.org/faq#q-what-do-the-green-ticks-mean ).

Does anyone know what the second tick in a group-chat exactly means?
Does it mean one person has read the message? Or all people in the group? Or maybe half of them?
Same as in normal chat. One person read message.
  -- DrKLO (github.com)


Source: https://github.com/DrKLO/Telegram/issues/397