The 7 layer model has often been extended in a humorous manner, to refer to non-technical issues or problems. A common joke is the 9 layer model, with layers 8 and 9 being the "financial" and "political" layers.
Network technicians will sometimes refer euphemistically to "layer-eight problems," meaning problems with an end user and not with the network.
Carl Malamud, in his book "Stacks," defines layers 8, 9, and 10 as "Money", "Politics", and "Religion". The "Religion layer" is used to describe non-rational behavior and/or decision-making that cannot be accounted for within the lower nine levels. (For example, a manager who insists on migrating all systems to a Linux platform "because everyone else is doing it" is said to be operating in Layer 10.)