Auditors and regulators are reminding firms to look closely at their accounts pa

Auditors and regulators are reminding firms to look closely at their accounts payable to be sure they haven’t inadvertently created debt that might alter leverage ratios and violate other loan covenants.
What type of debt are they referring to?
What are some examples of situations / structures that might appear to be operating A-P, but in face should be classified as long term debt?
Discuss the advantages and disadvantages of these various situations / structures?