'o'

The letter 'o' is based on an ellipse.

'b, p & r'

The letters 'b, p, & r' are all based on the use of a straight upright and an ellipse.

'p'

The letter 'p' is similar to the 'b', except the relative location of the ellipse and the straight line.

'r'

The letter 'r' is similar to the 'p' as shown. Note the final serif on the 'r'.

's'

The letter 's' is formed of two ellipses

'k'

The letter 'k' consistas of two straight lines and an ellipse