In artwork, a transparent or translucent covering over the copy where color breaks, instructions, or corrections are marked. Concerning mailing lists, a technique of overlaying (or adding) data information from one mailing list onto (or melded into) another list. Generally done in the effort to create a highbred mailing list, or to select a special group out of the whole.The transfer can be demographics, or a telephone number, or a job function, even psychographic data on buying habits. Can be utilized for other research purposes.