Cloning is the most powerful feature of SCL web animation. Cloning a sprite makes a copy of that sprite plus all of its properties and alterations. When cloning a sprite you can clone the sprite as it was originally defined or as it currently is.
Cloning is done inside a routine with a command like "clone from fan as newfan using original". Normally you want to change some properties of your clone to differentiate it from the original. You do this with the standard update commands provided in routines. When changing a clone, you can conveniently refer to it as _clone thus allowing code like "update sprite _clone where x=100". You do not need to give clones a name, for example "clone from mySprite using current"
Cloning from _sprite is not supported. It should be and we'll get there.