Standard icons or symbols used for press?

Question

I am fairly new to package design and even newer to Ai... my question is this: i am providing files to a company that has their packaging printed in China. so far things go pretty smooth but every now and then they miss something... i am need of icons or symbols that might be an industry standard for such things like "this color does not print".
another icon or symbol that would be handy is one that denotes a "transparent" or "clear" material or sticker/substrate.
to expound further on this, one project calls for white lettering on a clear adhesive backed material for a warning label on a bike. i put a gray background behind it so that they can see the lettering and i lock that gray layer and make it so it can't print, but in one instance they messed with the file and printed that layer (yes, i supply the raw Ai files with all the layers... long story, this will be another question at another time). i just want a way to note that the "gray color does not print" or something along those lines.
also, is there a standard style of line and/or color of line to show the dieline or cut line of the package? fold lines?
any ideas? i did some googling without too much luck.
Thanks for any help for a newbie...
-Mike

Answer 1

that's what i was afraid of... we've sort of been flying by the seat of our pants on most of this...  the language barrier sort of gets in the way of simplicity... we have talked about getting chinese symbols for what we are after but there hasn't been a clear consensus of even what those should be but maybe that should be revisited. It's amazing how different the workers see things from factory to factory over there. Thanks.