I, too, am puzzled by the language used for incidental uses since a smoke partition has been in the IBC for nearly twenty years. What I have done for situations where a sprinkler system is permitted in lieu of fire barriers, I use smoke partitions because they achieve the same result and are easier to describe on a set of drawings. I have had no pushback from plans examiners when I have done this (as a matter of fact, I describe this in my book).
When incidental uses were introduced with the 2000 IBC, there was no smoke partition assembly, so they used a descriptive/performance requirement. The smoke partition was added in the 2003 IBC to easily describe the corridor walls used for Group I-2. However, it has never been picked up to describe walls for incidental uses.
There are several things I would like to change in the IBC and other codes but I have not had the time or inclination to dive into cdpAccess to propose changes. Now that I have been more involved in the current code development this cycle, I plan on making several changes during the next code cycle, and this situation will be one of those proposals.
