Regularise use of repeats, tune (A/B/C etc.) markers and final bar. 1. Only show tune markers when a tune change is in the middle of a line. 2. Only show repeat starts |: if the repeat start is in the middle of a line. 3. Final bar end mark must be a thick line. The official rules for a repeat are that if there is no left repeat marker |: then the repeat starts at the previous double bar.

X: 1
T: Constant Billy
A: Headington
M: 6/8
L: 1/8
P: A(AB)4
K: G
P: A
D |: "G" GBd B2 B | "D7" cBc A2 A | "G" BAG "C" EFG | "D7" DEF "G" G2 D :|
P: B
|: "G" Bcd "C" ecB | "D7" ABc "G" dBG | "G" Bcd "C" ecB | "Am" ABc "D7" def |
"G" g2 d B2 B | "D7" cBc A2 A | "G" BAG "C" EFG | "D7" DEF "G" G3 :|