with -l, scale sizes by SIZE when printing them; e.g., '--block-size=M'; see SIZE format below

The option `-l` in some commands (such as `ls`) instructs the command to display the long format listing of files and directories. The option `--block-size` with an argument `SIZE` can be used with the `-l` option to scale sizes by `SIZE` when printing them. For example, `--block-size=M` will display sizes in megabytes. The `SIZE` argument can be specified using various size format options such as `K` for kilobytes, `M` for megabytes, `G` for gigabytes, etc.