Dear R Devel, I realized that I've been reading something without really thinking about it. In "?matrix" we have: byrow: logical. If 'FALSE' (the default) the matrix is filled by columns, otherwise the matrix is filled by rows. I don't understand on the first reading what "by columns" means. An experiment ("matrix(1:6,ncol=2,nrow=3)") shows that it means "one column at a time" rather than "rotating through the columns" as I had first imagined. However, the purpose of my looking up this documentation was to remind myself of the order of matrix elements in R; since I had to do the experiment anyway, I think the documentation added a useless delay. Perhaps this could be fixed if we define the meaning of "by columns" in the documentation? Apparently this is the same as "column-major order", but I am usually just as unfamiliar with the meaning of this other phrase. I would like the documentation to define both phrases, for example: byrow: logical. If 'FALSE' (the default) the matrix is filled by columns, i.e. in "column-major order", meaning that matrix elements in the same column are assigned consecutive data elements. Otherwise the matrix is filled by rows. Is that too wordy? Thank you, Frederick