Range: comma delimited list of property names
This attribute contains those properties that are potentially editable by the end user, separated by commas.
For the potential to be realized, the properties must be bound to controls, using the
bind attribute of the
editable: comma delimited list of property names
id: single word string identifier, starting with a letter
length: floating point number (frames)
composites: valid video or image media id
scale: comma delimited percentage values
symbol: a valid SWF URL, followed by an ampersand and class name
type: the string 'effect'