In honour of the IA Institute (IAI), in this post I will refrain from calling Big IA "UX".
During the IA Summit the IAI's Board of Advisors met and discussed the legitimization of the field of IA. Jess McMullin asked me to explain the t-model to the advisors and from that moment on it was used to frame parts of th ediscussion. Questions like "what skills should the IAI promote as core-IA skills?" and "should we claim the title of UX?" were answered by the advisors while they were pointing at parts of the t-model.
In the process, Harry Max extended the model in a way that fits well with my interest in the business side of IA: a layer of Business IA was placed on top of the horizontal UX band. This would include subjects such as "ROI for IA", "selling IA", "IA's organizational impact", "managing IA" and "IA processes".
When we were discussing the idea that the IAI should protect the corners of the t-model, someone jokingly came up with "Armpit IA" for the area which I dubbed guerrilla IA earlier: the area where the cross-over occurs between shallow IA methods with those of other fields. Of course this was quickly followed by "Shoulder IA" for those areas where Business IA methods cross-over into business-related methods of other fields.
So, the t-model is now cross-shaped and I want to be a Shoulder IA.