On the subject of Technical Debt, Martin Fowler identified a TechnicalDebtQuadrant in which technical debt is classified as either Deliberate or Inadvertent and either Prudent or Reckless.  He then makes the case that software projects can reasonably see all four combinations, including Prudent/Inadvertent — even though he can’t think of a real-word analogy that can be used to describe it to management.

How about this? It’s the year 2006 or so.  You’re building a custom house and specify that all rooms should be wired with Cat5 cabling.  By the time you move in, the cost of WiFi has dropped and the reliability of the technology has improved to the point where you decide to spring for an 802.11g hub so that you can easily moved from room to room with your laptop without having to connect it to a wall jack.  So, for the next 30 years, part of your mortgage payments will include paying for those Cat5 cable runs that sit unused in your ceilings and walls.

There.  Inadvertent debt that was prudent at the time that it was incurred.