The word **档子 (dàngzi)** is a compound noun formed through lexicalization, where the root character **档 (dàng)**—which originally connoted crosspieces, shelves, or categories (as in 档案, *file*)—is combined with the nominalizing suffix **子 (zi)**. This suffix often denotes a concrete or abstract *type* or *instance* of something. Thus, **档子** semantically evolves to mean a specific *grade*, *level*, *batch*, or *category* of things (e.g., 这一档子事, *this kind of matter*), and in colloquial use, it can refer to a *stall* or *booth* (a designated category of space), showcasing how the suffix generalizes and concretizes the root's classificatory meaning.