What type of written or visual communication is NOT appropriate on the work site?

Effective communication on a work site needs to be clear and unambiguous for all workers. Therefore, acronyms and textspeak in a written message (D) are generally not appropriate as they can be easily misunderstood or not understood by all individuals, potentially leading to errors or safety issues. Legible handwriting (A), clear sketches (B), and simple hand-drawn maps (C) can be effective communication tools. (Fundamentals of Crew Leadership, Fourth Edition, NCCER, Section 6.1.3 Choosing Appropriate Communication Methods)