163 Italic ambigram

This comes from Calligraphy Alphabets Made Easy.  That's why it tells you to "turn the book around..."

Italic Ambigram makes an asset out of our alphabet's oddity--that some letters become different letters when you rotate them 180°.  No other writing system does this; in early Greek, for instance, letters and their mirror images were read as the same letter. Rotatability makes Italic easy for beginners, since once you learn p you know d, h and y, u and n, and so on.  It also, however, partly explains the prevalence of  dyslexia among those who read and write using the ABCs.  

There are four levels of transformation by rotation, from no-brainers to real challenges.

1. Some letters virtually don't change: o, z, s, x.  You could cross t in the middle, omit the dot over i.  
2. Many of the letters are simply transformed into other letters when rotated; d to p; b to q; n to u.  
3. Some are somewhat the same: h and y; f and j; m and w.  
4. A few stubborn characters just won't change into anyone but themselves, and you have to hope that the context will make them readable; v, k, c.  These are indicated as outlined letters above.  

Try rotating sample words 180°.  Some stay the same: bug is still bug.  But noh becomes you; sung becomes buns; did becomes pip, and my favorite, mom becomes wow.  Try it! 

Ambigrams were pioneered as "inversions" by Scott Kim.