Do you mean shares acquired at a discount so income tax applies (on the market value at the time they were exercised/acquired minus the discounted price) and CGT also applies (on the disposal price minus the market value at the time they were acquired/exercised)? Say you acquire shares through an employee stock purchase plan (ESPP) as follows:
Discounted exercise price: €8
Market value at the time of exercise: €10
You hold onto them for a while and then sell them for €15
This means that you owe income tax (0%, 20% or 42%) on €10 - €8 = €2 per share and CGT (20%) on €15 - €10 = €5 per share (less the usual CGT allowances etc.).
Make sense?