Final answer:
The primary restriction of the Interspecies Cultural Exchange program is that liminals must wear disguises at all times.
Step-by-step explanation:
The primary restriction of the Interspecies Cultural Exchange program is that liminals must wear disguises at all times.
Based on the given information, the program requires liminals to adopt a disguise to hide their true identity while participating in the cultural exchange activities. This restriction ensures that liminals can blend in with humans and prevent any potential disruption or discomfort within human society.
For example, a liminal who is a supernatural creature with non-human features may wear human-like clothing and accessories to conceal their true nature while interacting with humans.