DDSXTY11 — Not every application limits itself to only 1 representation of a topic

Section 7.6.1 states that every component only uses 1 representation of a topic type.
Some generic services (e.g. durability service or a logger) might discover a topic from another node but will still be able to handle all representations of it, without ever having type specific knowledge hardcoded into them.

Corrected paragraphs:
Typically, in application code, a topic is associated with a single type (as has always been the case in the [DDS] API) . Therefore, multiple API topics may correspond to (different views of) the same network topic. A given reader or writer endpoint is associated with one of them. See Section 7.6.3, “Local API Extensions”, for definitions of the programming interfaces that support this polymorphism.
Generic services (e.g., logger, monitor) may discover a topic associated with one or more types. Such services may be able to handle all representations of the types, without ever having type specific knowledge hardcoded into them.