The following directive names are reserved and implemented within Radian: <area>, <background>, <bars>, <lines>, <metadata>, <palette>, <plot>, <plot-col>, <plot-data>, <plot-grid>, <plot-options>, <plot-row>, <points>.
The following attributes names are reserved for use by Radian directives: axis-x, axis-x-label, axis-x2, axis-y, axis-y-label, axis-y2, banded, clip-x, clip-y, cols, error-for, fill, fill-opacity, format, id, interp, label, legend-switches, marker, marker-size, name, range, range-x, range-y, rows, select-x, select-y, separator, src, stroke, stroke-opacity, stroke-switch, stroke-width, tabs, title, type, units, x, x2, y, y2, zoom-2d, zoom-x, zoom-y.
Any other attribute name applied to a plotting directive brings a name into scope for data access expression evaluation.