Our summary
This World Bank handbook, published in 2013, was written for people involved in public procurement. It describes common fraud and corruption schemes and the warning signs — red flags — that point to them at each stage of the procurement process.
Although aimed at the public sector, most schemes it describes, such as bid rigging and conflicts of interest, also occur in private companies.
How auditors use it: to build procurement audit programs and to train buyers and approvers on what to look for.