SUMMARY: This document proposes to amend Federal Motor Vehicle Safety Standard (FMVSS) No. 213@ Child Restraint Systems@ regarding a Hybrid III 10-year-old child test dummy that the agency seeks to use in the compliance test procedures of the standard. This document supplements a 2005 notice of proposed rulemaking (NPRM) and a 2008 SNPRM previously published in this rulemaking (RIN 2127?CAJ44) regarding this test dummy. In the 2005 NPRM@ in response to Anton's Law@ NHTSA proposed to adopt the 10-yearold child test dummy into FMVSS No. 213 to test child restraints for older children. Subsequently@ to address variation that was found in dummy readings due to chin-to-chest contact@ NHTSA published the 2008 SNPRM to propose a NHTSA-developed procedure for positioning the test dummy in beltpositioning seats. Comments on the SNPRM objected to the positioning procedure@ and some suggested an alternative procedure developed by the University of Michigan Transportation Research Institute (UMTRI). Today's SNPRM proposes to use the UMTRI procedure to position the test dummy rather than the NHTSA-developed procedure. We note that the 10-year-old child dummy may sometimes experience stiff contact between its chin and upper sternal bib region which may result in an unrealistically high value of the head injury criterion (HIC) 1 referenced in the standard. Accordingly@ NHTSA proposes that the dummy's HIC measurement will not be used to assess the compliance of the tested child restraint. This SNPRM also proposes other amendments to FMVSS No. 213@ including a proposal to permit NHTSA to use@ at the manufacturer's option@ the Hybrid II or Hybrid III versions of the 6-year-old test dummy@ and a proposal to use the UMTRI procedure to position the Hybrid III 6-year-old and 10-year-old dummies when testing belt-positioning seats. 1 Throughout this document@ HIC refers to the head injury criterion computed using a 36 millisecond (msec) time interval.