If you're looking for fairly obvious literary conventions, I'd suggest:
- Constantly holding, instead of pocketing or bagging, their readers;
- Showing off with literary quotes;
- Glasses.... possibly a future reader tool, the text is displayed on the glasses, giving the person a faraway look at all times;
- Highly intelligent;
- Small and nerdy-thin, pale in pallor, perhaps slightly anti-social or overly shy and quiet;
- One or two humongous hardback antiques in their possession, which they only admire, but never read (they have the full text in a digital format, and use that).