Vocabulary selection for graphic symbol-based augmentative and alternative communication systems is important to enable persons with significant communication difficulties to express a variety of communication functions to indicate needs and wants, to develop social closeness, and to fulfill social etiquette. For persons who experience pain, abuse, bullying, or neglect, it is essential to be able to communicate about sensitive issues. However, published core vocabulary lists allow limited scope for communicating about sensitive topics, due mainly to the techniques employed to determine such lists (e.g., observations or recording of communication patterns of peers with typical development during fun-based or daily activities). This article is based on the outcome of a study of children's pain-related vocabulary. Based on the study, we propose a model for selecting vocabulary on sensitive topics. The model consists of four phases: (1) using hypothetical scenarios; (2) considering different perspectives that may affect vocabulary selection; (3) involving direct stakeholders, and (4) customizing vocabulary.