The Sign Command
The sign creates a sign object containing the specified text. Only certain objects support the sign command. In order for sign to work, the object must have a polygon or polygons with a tag value of 100 to indicate where on the object the sign text should be placed. Horizontal signs are currently not supported.
"Sign text" is the text for the sign. If omitted, the sign text defaults to the contents of the object's description field (this is the most common form of the sign command.) If specified, the sign text must be enclosed in double quotes.
The color argument specifies the color to use for the sign text, and bcolor specifies the sign's background color. Both arguments are optional. The default color scheme is white text on a blue background. The colors can either be specified as one of many preset word values or as a "raw" hexadecimal value giving the red/green/blue component values (the same format as used for the BGCOLOR= HTML tag).
The optional name argument specifies the name of the object to place the sign on. Object names are assigned via the name command.
This creates a sign using the default color scheme and containing whatever text is in the object's description field.
This creates a sign which says "Warning!" in a rather garish color scheme.