Output consisting of more than one line, e.g., paging the command buffer, is directed to the text window. Extra white space at the beginning of a command line or between arguments is ignored. In this text, igi commands are always written in upper case. Macro names are represented in lower case. Command arguments are written in lower case and optional arguments are enclosed in square brackets.
Many commands belong to a family of commands.
That is they are the same in syntax and semantics but operate on a specific instance of some category. They all draw a line, but operate in different coordinate systems. These families of commands are usually.