What is the difference between P22h, E22HA & E19?

What is the difference between the following three bulbs P-VIP 120-132/1.0 P22h P-VIP 120-132/1.0 E22HA P-VIP 120-132/1.0 E19 P stands for parabolic reflector. E is for elliptical reflector. The 19 and 22 denote sizes.