In principle you can post about any topic you can think about. At first read.cash had topics, next the idea was to let communities stand for a topic. Keep in mind if people search the internet for a certain topic, answer to be questioned articles/sites will be shown. This isn't different with what is written here. If you write an article make clear what the topic is, write a clear text and add it to a community that fits! Read the rules given by the community. There can a limit of words be asked. Grammar or a certain language only can be a deal too. 🍀💕