More Variable Attributes:
Multiline: Forces a string variable to show up in the Inspector as a multiple-line text input box, rather than a single line.
TextArea: Similar to Multiline, this allows for multiple lines when editing a string variable, however this attribute adds a scroll bar function when the text goes out of view.
Space: Very simple. Just adds a slight space between the previous and next variable.
Tooltip: Adds a helpful (or not) message that appears when you hover over the Inspector variable.
ColorUsage: Changes how Color variables appear in the Inspector. This can make them be treated as HDR and/or show the Alpha (transparency) value.