When a new topic is created in a category or tag that you have the notification level set to Watching First Post, you will be notified when the topic is first created.
After being notified about the topic creation, the topic will default to the “Normal” notification level, unless you manually change the notification level for the topic, spend enough time in the topic to automatically track the topic according to your Automatically track topics I enter preferences, or post in that topic depending on your When I post in a topic, set that topic to preferences are set to.
Unless a topic is set to “Watching”, you will not receive notifications for edits.
Notification levels can always be set per topic manually to override any default preferences. If you want to be notified about topic edits for topics that you are “Watching First Post” you would want to make sure that the topic gets set to “Watching” after being notified about the topic creation. Alternatively, you could set your notification preferences for those topics to “Watching” instead.
“Watching First Post” allows users to receive notifications for just the first post in each new topic within specific categories or tags, whereas “Tracking” will provide a count of new posts next to the topic. This means that “Watching First Post” will only provide one initial notification for topic creation, instead of a count of new posts in a topic.
The “Watching First Post” notification preference is useful when you want to be notified about the creation of new topics but do not necessarily want to receive notifications for every subsequent reply or post within those topics.