<span style="font-family: Arial">Rusty,
If I recall, at least pre 1977, the numbers could be on the fuse sideswith therecommendation they be precceded with the 'N".
Per the AMA website for pattern, currently it states:

</span><font size="2">4.7: Identification. </font><font face="Times New Roman,Times New Roman" size="2"><font face="Times New Roman,Times New Roman" size="2">All models shall be identified by the contestant&rsquo;s AMA license number permanently affixed to the upper side of the right hand lifting surface or to each side of the fuselage or vertical stabilizer. The height of the numerals must be at least one (1) inch. Both stroke and width shall be such as to enable ready recognition. </font></font><font size="2">

4.7.1:</p></font><font face="Times New Roman,Times New Roman" size="2"><font face="Times New Roman,Times New Roman" size="2">Borrowed or shared aircraft shall carry temporary identification, as shall repaired aircraft if deemed necessary by the Contest Director. Such identification shall consist of the AMA license number of the contestant operating the model affixed to or written on the model in any way which conforms to the standard set forth in 4.7. Temporary identification numbers may be affixed in any manner which will withstand the rigors of flight. </font></font>