Choosing a category for a new topic
Anyone creating a topic and is uncertain what is the best location
Categories are meant to be a way to collect together topics with a similar subject matter. Similarly sub-categories are groupings within the top level category.
Many of the top level categories correspond to ACCESS-NRI Working Groups. If your topic is clearly within the scope of one of those working groups then that is the obvious category to use.
If your topic is very technical in nature, but not specific to one of the working groups, say a #python question, then the #technical category would be a better choice. As it is more likely to be seen by a wider audience, and particularly those with an interest in programming and other technical topics.
If your topic spans multiple categories, choose one that seems the best fit and use tags to indicate the other subject areas that are relevant. This will assist with discovering the topic.
If you’re confused about categories and tags, this is a great (short and easy) read.
It isn’t strictly necessary to use a sub-category, but if your topic is clearly related to a specific sub-category then it is a good idea to also specify a sub-category. It makes it easier to find your topic later and helps everyone to narrow down the list of topics displayed when browsing for information.
Select the category (and sub-category if necessary) in the drop-down menu of the edit window:
Creating a topic while browsing a category will use that category by default.
The how-to video for creating a topic mentions this.
If you want to change the category of your post, navigate to your post, click the pencil icon to the right of the title
change the category
and push the orange tick button to accept the change