[Clascomment] OPT-IN: Measurement of charged pion production in deep-inelastic scattering off nuclei with the CLAS detector23

[Volker Burkert]

Dear lead authors, 
It is good to see that these data are now ready for publication. Congratulations! 
I like very much the detailed discussion of all systematic effects. 
I don't have comments to the content, but just want to comments on the data presentation. 

1) This is a full paper and all the data points shown in the figures should be made available in the
 form of tables, with the exact values and uncertainties. There is no limit  
The data points are very close together in the figures are hardly readable. 

2) Once the data are tabulated, the figures should be used only to display the main features of their
 kinematic dependencies. 
For example in Figure 2,  I suggest to only include one Q^2 point, as the 
dependencies on "z" are very similar, and anyone interested in the Q2 dependence can pick the 
values of the tables (which is impossible to do from the graphs, anyway). 
The same holds for Figure 3, only use one Q^2 value. 
In figure 4 and in figure 5, I suggest to do the same, and include only one of the nuclei.  

3) Since the figures are all in color, which will not in the printed version, you need to put after the  
Figure X.(color online) before the caption.  Also, make sure that the various data markers and shadings
are clearly identifiable what they represent when printed in black & white. 

4) Figure 1. Don't put the legend next to the figure. There is plenty of space inside the figure frame 
to put the legend  above/below  the data points and curves. You may also consider showing each of the graphs 
separately in larger size at different aspect ratio, and with larger markers to make it more impressive.
 
   
5) Minor comments:
- line 37: "through nuclei" => "through the nucleus" (you talk about interaction of "an electron". 
   It will not go through several nuclei)
- line 238: "using the proton elastic reaction" => "using the elastic electron proton scattering process"
- line 707 - 712. There are 3 times phrases such as "the data could help/put.......". That is a very weak 
  results. Can the statements be made stronger and definitive. For example "The data will ..." .  

All the best,
Volker