Lexicalised concepts are represented in wordnets by word-sense pairs. The strength of markedness is one of the factors which influence word use. Stylistically unmarked words are largely contextneutral. Technical terms, obsolete words, “officialese”, slangs, obscenities and so on are all marked, often strongly, and that limits their use considerably. We discuss the position of register and markedness in wordnets with respect to semantic relations, and we list typical values of register. We illustrate the discussion with the system of registers in plWordNet, the largest Polish wordnet. We present a decision tree for the assignment of marking labels, and examine the consistency of the editing decisions based on that tree.