We are about to switch to a new forum software. Until then we have removed the registration on this forum.
The forum is structured in several categories, some having sub-categories.
Among other advantages, it allows people knowledgeable in a field to see if there are messages to be answered in their category.
So by choosing the right category, you increase your chance of being answered quickly and accurately.
There is no hard and fast algorithm to choose a category, but some guidelines can help you.
First, read attentively the category descriptions. Then, choose the most specific category appropriate for your message.
The forum is broken down in big categories which can have sub-categories.
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If you don't have a question or if your question is not programming related (or very generic), post your message in the General category.
The main category is for asking questions (or discussing) about the forum itself. Other general messages should go to General Discussion.
Share your Work or Events and Opportunities seem self-explict enough, they rarely get stray messages...
Likewise, this category seems explicit enough, getting rarely misplaced messages.
Just let me repeat this is not the place to ask questions about existing libraries, tools or modes (unless you develop them!).
It is the category with the most misplaced questions.
The Programming questions category should seldom be used: nearly all questions are programming-related, but generaly belong to one of the sub-categories.
If your sketch uses some hardware like a game controller or some input or output device, choose the hardware category.
We made two sub-categories for the most asked for devices: Kinect and Arduino. If you use these devices, choose the appropriate sub-category.
If your sketch uses a library (if it has an import statement not starting with 'java'...), put it in the Questions about Libraries category.
See the section on the message body about questions unrelated to the used hardware or library.
If your question is about a sketch you are working on, don't hesitate to show it. In this case, put it in the Questions about code category. Unless it uses some hardware or library. See above...
If you have not started a project or if you feel the question is not related to the current state of your sketch, post your request in the How to category. Most questions there can be started by these two words, from the simplest ("how to sort an array?") to the most abstract and difficult ("how can I reproduce the effects seen in this video clip?").