A command may be in upper or lower case letters, and may be abbreviated as long as it remains unambiguous. Special care must be taken with inputs requiring text strings where buried spaces are allowed. Any number of commands and command inputs can be typed on the line in one go. They must be separated by at least one space. This is recommended when dealing with an unfamiliar command.
Symbols are especially useful when creating macros.
Brace expansion of symbols were introduced in O version 5.10.3. All input can be typed in upper or lower case, or intermixed any way the user prefers. The view into the 3-D window is usually controlled by a set of physical dials. These dials are also used as inputs for many O commands. A mouse is used to pick atoms and items on a screen menu.