Compared to ISO 8859-1, code point 127 (0x7F) showed a medium shaded gray box like in the former HP Roman-8 based character set.
Code points 169 (0xA9) and 174 (0xAE) were now clearly defined as holding the copyright (©) and registered trademark (®) symbols in compliance with ISO 8859-1, whereas the corresponding glyphs still resembled the inverse circled numbers more.
Hewlett-Packard never defined an official Unicode translation, hence several variants evolved in the community, differing in code points 31 (0x1F), 127 (0x7F), 128 (0x80), 129 (0x81), 133 (0x85), 134 (0x86), 158 (0x9E), 160 (0xA0), 169 (0xA9), 174 (0xAE), 178 (0xB3), 181 (0xB5) and 223 (0xDF).
[14][15][16][17][18][19][20] The fact that the Unicode equivalent for x-bar at code point 129 (0x81) is a combination of two characters (x̅) could cause problems in translations, therefore it was suggested to use U+0101 (ā) instead.
[18][19][20] Characters which cannot be reasonably transcoded should be mapped to code point 127 (0x7F), similar to what the calculators do when communicating with older printers like the HP 82240A.