Overprint B group "b"
This overprint was used  on stamps Pofis / Trojan
number 52 - 54, 84 - 88 (air and postage due provisory, except 1h.)

Overprint B - group "b" - type I.

The height of the overprint is 10,5 mm, the length 20,5 mm.
The height of the letters is 2,6 mm, the angle is 28º.
1. The axle of  T passes the right part of  O and touches  the  right part of 1.
2. In the K is a small cut, the upper part of S has a deep cut.
3. The second 9 in 1919 is cut.

Overprint B - group "b" - type II.
The height of the overprint is 10,5 mm, the length 20,5 mm.
The height of the letters is 2,6 mm, the angle is 28º.
1. The axle of  T passes between O and V and between 1 and 9.
2. The K and S are without the cut.
3. The second 9 in 1919 is cut.

Overprint B group "c"
This overprint has been used on the stamp Pofis / Trojan 83 1h PORTO

Overprint B - group "c" - type I.

The height of the overprint is 10,5 mm, the length 20,5 mm.
The height of the letters is 2,6 mm, the angle is 43º.
1. The axle of  T passes the left part of  V and passes between
    1 and 9.
2. The hook over C is easy to see.

3. The second 9 in 1919 is cut.

Overprint B - group "c" - type II.

The height of the overprint is 10,5 mm, the length 20,5 mm.
The height of the letters is 2,6 mm, the angle is 43º.
1. The axle of  T touches the left part of  V and of the 9.
2. The hook over C is just a dot.
3. The second 9 in 1919 is cut.