At our meeting in Oklahoma several people asked for a reference to the FAR which validates the use of less than 12" high registration numbers on the Skymaster booms.
You will find this at 45.25 (b)(2) for the location and 45.29 (f) for the size.
The link for the FARs is
http://www.airweb.faa.gov/Regulatory...s.nsf/RGLAbout!OpenForm&Seq=1
