buffer local erc-hide-list

gistfile1.el

  (defvar qdot/erc-status-allow-list nil
    "alist of channels and the event messages to show for them.")
  
  (setq qdot/erc-status-allow-list
        '(("&bitlbee" . ("PART" "JOIN" "MODE" "NICK" "QUIT"))
          ("znc-bitlbee" . ("PART" "JOIN" "MODE" "NICK" "QUIT"))))
  
  (defadvice erc-hide-current-message-p (around qdot/erc-hide-per-buffer-advice last (parsed) activate)
    "Addition to hide message predicate to check for channel
  specific or network specific join/part showing. PART/JOIN/MODE
  messages can be parsed per channel. NICK/QUIT are parsed per
  network."
    (let* ((command (erc-response.command parsed))
           (command-args (erc-response.command-args parsed))
           (sender (car (erc-parse-user (erc-response.sender parsed))))
           (channel (if (member command '("PART" "JOIN" "MODE"))
                         (car command-args)
                       (buffer-name (current-buffer)))))
          (if (and (assoc channel qdot/erc-status-allow-list)
                   (member command (assoc channel qdot/erc-status-allow-list)))
              nil
            ad-do-it)))