Exchange of information requests: period until requested information is received is excluded from limitation computation. The amendment adds an exclusion in Explanation 1 to section 153 providing that the period from when a competent authority refers a request for exchange of information under agreements covered by section 90 or section 90A until the Commissioner receives the requested information, or until a prescribed maximum period if earlier, shall be excluded for limitation computation, and modifies the preceding clause to accommodate this insertion.