Know how to create statements that are meaningful, accurate and free from ambiguity and verbosity.
Make only one single point with a statement. Be clear about what this point is in as simple terms as possible. Don't try to make a statement look more impressive by adding complexity to it. Use straightforward, everyday language where possible. Don't include 'what ifs' within a statement. Keep the statement as short as possible.
The knowledge named 'compose concise statements' is considered to be very important.
In addition, the knowledge is thought to be quite complex and quite difficult to learn, it is mostly learned from experience, and is quite specialised knowledge.
Opinion is that it is quite justifiable knowledge.