Final answer:
It is true that a listing brokerage must keep records of failed offers, either through a summary document or the complete offer, for at least one year from the date of the offer to ensure compliance with real estate industry standards and regulations.
Step-by-step explanation:
The statement that a listing brokerage must keep either the summary document or the complete offer for each failed offer for one year from the date of the offer is true. Brokerage firms are typically required to adhere to specific document retention policies, which often include maintaining records of unsuccessful offers. These policies are in place to ensure transparency and accountability within the real estate industry and to comply with various legal and regulatory guidelines. The exact duration for retaining these documents can vary depending on local laws and regulations, but one year is a common practice.