Final answer:
When a physician treats another physician or allied health professional free of charge, it is commonly referred to as 'pro bono' or 'charity care'.
Step-by-step explanation:
When a physician treats another physician or allied health professional free of charge, it is commonly referred to as 'pro bono' or 'charity care'. This means that the physician is providing medical services without expecting payment.
This type of treatment can occur in various settings, such as academic medical centers, professional organizations, or as part of volunteer work.
Physicians may offer pro bono services to their colleagues as a way to give back to the medical community, support their peers, or help those in need.