This series of articles is similar to the letter type and is usually written by leading researchers, although not necessarily so!
Sometimes research reached new but limited results that are presented in a short format. The speed of reviewing and publishing this category of articles is higher than other types, which is a major advantage.
In fact, in these articles, results are concise and useful and rely on innovation and the importance of the subject. Some journals in this category of articles have limitations on the number of words or the number of pages that can be included.