The Big Ten exception in football is that an institution may oversign by 3. Our rule isn't based on the NCAA limit of 25 initial counters, it's based on the number of scholarships available. Using your example, if an institution has 65 countable scholarships returning, the institution could sign up to 23.
When we approved limited oversigning in 2002, part of the deal was that institutions that did oversign would need to provide "sunshine" to allow for peer review. This reporting includes identifying the individuals who received the offers that created the oversigned situation. In addition, institutions that actually oversign would need to provide a person-by-person accounting for how the institution comes into compliance with the NCAA limit of 85; this includes reporting on not only the new signees, but also the status of each student-athlete who received countable aid in the previous academic year.
Over the years, a few institutions have used the exception to oversign, but what we've seen is that the majority do not use the exception.