Bob Ryan filed his tax return and claimed a dependency exemption for his 16-year-old son Dylan. Both Bob and Dylan are citizens and residents of the United States. Dylan meets all the necessary requirements to be considered a qualifying child; however, when Bob filed the tax return he didn't know Dylan's Social Security number and, therefore, didn't include an identifying number for his son on the tax return. Instead, Bob submitted an affidavit with his tax return stating he had requested Dylan's Social Security number from Dylan's birth state. Is Bob allowed to claim a dependency exemption for Dylan without including Dylan's identifying number on the return?