"Regular" in this context mean the "normal", "usual" type of investment project, ie Big initial outflow (payment) at start, possibly followed by other outflows, and which are all themselves followed by net inflow.
Borrowing would be the reverse of this.
And there are possibly other more complex cashflow profiles, some of which may have many (numerical) solutions for the IRR, or possibly even no real ones. These "non-regular" ones shouldn't be cause for concern in the exam.
Last edited by a moderator: Apr 3, 2009