You have the ability to fine tune how you are notified about different posts / comments / mentions in each category / sub category of the forum. Just go to a category / sub category and select the circle button beside “+New Topic”. You will see a list of options of how you are notified about that category. This can be for a top level category or sub categories. So if you are strictly a CNC person and do not care about K40 Lasers you could completely mute the K40 Lasers category if you desired to do so.
