Comments on the paper "Measurement of Charged Particle Multiplicities in proton-proton collisions at a centre-of-mass energy of $\sqrt{s} = 7$ TeV in the forward region, LHCB-PAPER-2011-011-001 (Version No. 1). General: 1. Section 5.3, The section on the "unfolding procedure", essential for the analysis, is difficult to understand. 2. Results: The asymmetry (Figs. 4 and 7) raises questions. The asymmetry must be understood, before the conclusion of the paper - that all event generators fail to describe the data - can be drawn. 3. All Figs., but especially Fig 1 and 5, are much too small 4. MC seem to have an air-filled VELO. Is this taken into account? how has this effect been excluded in the analysis? (Detailed comments on textual changes below) Sect 2, line 244 : is beam tilt not relevant? Sect 2, line 251: "3.7 Tm". in several publications it is "4 Tm". please, verify, and/or correct. S2, l. 278: What is HLT1 efficiency? S3, l. 285: "description corrdct within 10 %": please give reference! S4, l. 299: "The data were collected ... crossing was low." Need quantification. What is average pile up? Is there a correction incorporated? How was this done? S5.1, l. 336: "..."efficiency ... typically > 90 %, while it is at least 85 % in the backward direction." This must be quantified. E.g., "at least 85 %" can also mean: "100 %". One needs to know the probability to detect a track in a given eta-region, not global numbers. Please, provide a plot (or information on) the efficiency as a function of the rapidity. Section 5.3 - Unfolding procedure. This section needs to be written in a more understandable way; even for people from LHCb it was not clear before reading it twice. It is not clear why an unfolding procedure is applied, why not simple scaling? S. 5.3, l. 369: Doesn't the value of the Poisson probability depend on the velo occupancy?? S. 5.3, l. 379 : "The procedure ... simulations." What is the uncertainty?? S. 6.3, l. 409: "3.7 %" : Why not simply downscale by this factor? At the end of this paragraph, 1/2 page further down, you come to the same result "3 - 4 %" (l. 420). S. 7, l. 441: "KNO variable" : what is the use of this variable? why has it been used here? Is it still considered to be valid at LHC energies?? S. 7, l. 445: "self-consistent". What is meant by this word? From the fig., we take that there is no variation on eta. So what is shown by this discussion? S. 7, Fig. 1, : These figures are MUCH TOO small. S. 7, Fig. 1, : there is a strange behavior of the error band around the data points (shaded area). why does it vary within a given datapoint?? S. 7, Fig. 2, caption: "indicated in the key" . What is meant by this? Do you mean the text in the inserts? S. 7, plot 4: The asymmetry between backward and forward data is very troublesome. A priori, one expects a symmetric distribution, and this should be understood by MC. The two facts that neither the distribution is symmetric, nor that it is understood by MC, raises seious concerns about the validity of the results. S. 7, fig 5: Way too small. S. 7, Fig 6, caption: "in the key" . see above. S. 7, Fig 7, caption: "in the key" . see above. Detailed textual comments: l. 218: "allows it to probe dynamics of the collision" -> "allows to probe the dynamics of collisions" l 219 : "charged-multiplicity" -> "charged particle multiplicity" l. 268 : "(after the magnet.)" -> "(after the magnet)." l. 281 : "for acceptance, resolution effects ..." -> "for acceptance, efficiency and resolution effects ..." l. 293 : "were decayed" ?? this is not English. You mean something like: "The decay of secondary particles were followed by GEANT4" l. 295: " ... events in both... " -- do you mean: "equally distributed over both ..." or: "taken at each of the two magnet settings" ?? l. 303: "fakes track" -> "fake tracks" l. 306: "a cut of less than 4 missing VELO hits compared to that expected is applied" -> "a cut of at most 4 missing VELO hits is applied" l. 309: "both" -> eliminate, no use here. l. 336: "(includinga acceptance)" -> "(includinga acceptance effects)" l. 354: "detector material" : please, add a Reference! l. 355: "generator that of Lambda" -> "generator , the production of Lambda" l. 355: replace the "wiggle" by the word "approximately", and add a references l. 379: "The procedure had been ..." -> "The procedure has been ..." l. 430: "unfolded charged particle , n_ch, multiplicity distribution"-> "distribution of the unfolded charged particle multiplicity, n_ch," l. 438: "description of the data; this tune ..." -> "description of the data. Note that this tune ..."