Though a petnames interface will resemble existing contacts lists, there are significant incentives for dishonest actors to attempt to game any interface that combines Declared names, Edge names, and Pet names.
Petnames are 1-1 mappings; contact lists are not. (I have two entries for my son, one under his given name and one as ICE for In Case of Emergency.) I wonder if the way contacts lists work is better because they allow you to have different contexts for a single person.
The “unprintalbes” in the title raises the interesting question of character set. ASCII isn’t very nice to speakers of many languages, so what should we choose? Or do we have to choose? Can we make the choice part of the connection set up protocol? We did a simple version of that in Client Utility, negotiating such things as ASCII vs. EBCDIC and byte order. (Both got dropped in the E-speak product.)
bloody use unicode, with utf8 encoding, if you are afraid of glyph order reversal then you could use case sensitive punycode like international aware domain names do and show that in smaller less contrasty font below the full glyphs string displayed or as a tooltip above the aforesaid full glyph string.
@chip can attest to the various ways we Icelanders and of other countries have learned to encode our non ascii characters.