In Preferences -> Filters you can add or edit filters to omit messages to be shown. Message are simply discard if any of the filters match a message. Filters currently have 5 fields to choose what you would like to filter out:

Protocol: You can choose whether to filter out messages in IRC or in Twitter Chat Type: Group/Public would be the #channel or Home Timeline, Person/Private would be a query or direct message, Protocol/Server means for example all message on irc.oftc.net Name: here you can specify nicks/channels etc. which are fitting to the prior options Type: An event would be things like join/part/name changes and so on, while a message means actual messages written by a user or a bot Pattern: The pattern field describes which kind of words/events you would like to filter out.

It is possible to leave out e.g. pattern field so all events could be filtered at once. If you would like to see name changes but no join/quit/left messages you could use regex to setup a filter for more than one word.

For example enter

/(join|left|quit)/

/^ |^*  nick /