What is the ruling on a doctor taking another doctor's clinic sign and placing it on his own private clinic, and is his livelihood considered unlawful, regardless of whether the owner of the sign forgives him or not?

The question was not fully understood, but it was gathered that the questioner opened a clinic under his name and then handed it over to another doctor. After the questioner traveled, the doctor took the sign and hung it on his own clinic. If this is what happened, then the doctor combined a breach of trust with lying and deception. However, this does not nullify the reward for his work if he fulfilled the patient's right to treatment. As for the questioner's financial right against the doctor, this depends on whether the sign is considered a trade name, which contemporary scholars consider a financial right that its owner is allowed to benefit from and which prevents others from infringing upon it. He has the right to demand fair compensation if it is used without his permission.