Article 145 3.

Where the institution extends the use of the IRB Approach subsequent to its initial permission, the experience of the institution shall be sufficient to satisfy the requirements of paragraphs 1 and 2 in respect of the additional exposures covered. If the use of rating systems is extended to exposures that are significantly different from the scope of the existing coverage, such that the existing experience cannot be reasonably assumed to be sufficient to meet the requirements of these provisions in respect of the additional exposures, then the requirements of paragraphs 1 and 2 shall apply separately for the additional exposures.