It is a common practise to use simile marks for repeated chords.
This simplifies the chord sheet and makes the actual chord changes more obvious.
%
Simile mark, playing instruction to repeat one preceding bar
%%
Simile mark, playing instruction to repeat the two preceding bars
Reprint preceding bars
Short cuts for the lazy ones to enter multiple bars of the same chords.
%1
Reprint the preceding bar
%2
Reprint two preceding bars
%4
Reprint four preceding bars
= Have a look at the source!
- Reprint a single bar
A B C %1
- Two reprint in a row
A B %1 %1
- Reprint two bars
A B %2
- Reprint 4 bars
A B C D
%4
- Simile marks
A B % %
E F %%