The sumif() function allows cell reference in its 'criteria' parameter, like: SUMIF(G4:G66;"="&G68;D4:D66) where G68 contains the index, for example numbers 1,2,3. According to the (en) help each function needed specific "=1", "=2" and "=3" criteria. I only found the above solution in online forums - for Excel ;-) - but it works also in LO. Solution: Add the ".."&cell-reference Option to the Help text.
Since you are talking about the English help text, it sounds like a documentation issue instead of a localization one to me. Let's change the component and ping the documentation people and see what they say.
Fine with me, I did not see the 'documentation' option.
Ok, the section is https://help.libreoffice.org/latest/en-US/text/scalc/01/04060106.html#Section15 If you want, you can propose the explanation that should be added and the location of where it should be inserted.
I guess the point here is just that only 1 example is given, because the text clearly says : A criterion is a *single cell Reference*, Number or Text For the sake of closing this "bug", I'm adding a link to COUNTIF, to emphasize it gives more examples. See also many more examples here : https://wiki.documentfoundation.org/Documentation/Calc_Functions/SUMIF
R U Sirius? Four years after reporting this deficiency in the help files, the best solution is to add a link to another function with the same situation? Help is there to -explain-, not to give examples. Add the proposed text, then you can close this bug.