Final answer:
Corrie ten Boom and her family used coded language in their phone conversations to protect their resistance work and the Jews they were hiding from the Nazis during World War II.
Step-by-step explanation:
In the context of World War II, Corrie ten Boom and her family used a coded language to keep their phone conversations incomprehensible to the Nazi occupiers and protect their work in the Dutch resistance. For instance, they would refer to the Jews they were hiding as 'watches', which was fitting given their family profession in watchmaking. This use of code words made it difficult for anyone listening in to understand the true nature of their conversations, thus safeguarding the people they were protecting and their resistance operations.