Final answer:
Nonverbal communication includes facial expressions, body language, and visual symbols such as displayed tattoos or messages on attire. Speaking in a loud voice is not considered nonverbal communication but can include nonverbal elements through tone and volume.
Step-by-step explanation:
Forms of nonverbal communication include various methods through which people convey messages without the use of spoken words. These can include facial expressions, body language, and visual symbols that may be culturally specific or universally understood. When it comes to the examples provided, wearing a shirt with a message on it, making a disgusted facial expression, and displaying tattoos can all be considered forms of nonverbal communication. Speaking in a loud voice, however, is a verbal method of communicating, although the volume itself could convey additional nonverbal cues.