if i have a facade of a building with 100 windows, i can make a reference file for that window, and then if the design changes i only have to modify the source windows, then all other will update automatically. its that correct??
Well yes, but in that instance (a window) it would be a lot better to use a symbol instead. XRef's are better for portions of a plan/section/elevation to be used as a detail. Like a stair plan that uses a portion of the full plan.
While I agree with your basic premise, I don't necessarily agree that symbols would be a better way to go with the windows example. After they are change symbols have to be updated in every file in which they occur. So if someone forgets to update the symbols in one file, then the windows in that file will be wrong. While ZREFs are automatically updated every time the file is opened. So I am not sure symbols are better in that instance. Having said that, I would use symbols also.
I like Paul's idea on using the xrefs for that type of use, my only concern would be that the xrefs once you get up to about 50 or so seem to really slow things down. I wish there was a way to get drawings to always update their symbol definitions from their source (hard drive, network location) when the file is opened, saved or regenerated and only use the drawings internal symbol information only if the external information is not available, like when sent to a consultant. I'm constantly having to Reload all symbols to get my symbols to update.
Thanks! - Josh Do. Or do not. There is no try. Josh's Digital Downloads is come back online soon. Stay tuned. (soon is a relative term)