Final answer:
A support salesperson who advises on product specs and system design is usually called a technical sales representative or sales engineer, contributing their expert knowledge to aid customer decision-making.
Step-by-step explanation:
A support salesperson who usually advises customers on product characteristics and application, system design, and installation procedures is typically known as a technical sales representative or sales engineer. These professionals play a crucial role in helping customers understand the technical aspects of a product or system and how it can meet their needs. They combine their technical knowledge with sales skills to provide advice and support on a range of products, from software to industrial equipment.