frangible and usually contain a barcode for electronic identification using readers. For example, the US Military uses a UID system for its assets. Shelf / Rack labels The storage locations in shelves are often marked with a shelf label (possibly also with a barcode or numbering). They can be self-adhesive, magnetic or slide-in. Textiles Garments normally carry separate care/treatment labels which, in some regions, are subject to legislation. These labels typically indicate how the item should be washed (e.g., machine washed vs. dry cleaning), whether bleach can be used. Textile labels may be woven into the garment or attached, and can be heat resistant (so survivable in hot-air dryers and when pressed), colorfast (so does not bleed onto the garment), washable, leather or PVC/Plastic. Printed labels are an alternative to woven labels. Some upholstered furniture and mattresses have labels that are required by law, describing the contents of the stuffing. Textiles containing pesticides as an ingredient may also require government approval and compulsory labeling. In the USA, for example, labels have to state the pesticide registration number, statement of ingredients, storage and disposal information, and the following statement: "It is a violation of Federal Law to use this product in a manner inconsistent with its labeling”. A label including a company name or identification number and a material content list may also be required. Mailing Mailing labels identify the addressee, the sender and any other information which may be useful in transit. Many software packages such as word processor and contact manager programs produce standardized mailing labels from a data set that comply with postal standards. These labels may also include routing barcodes and special handling requirements to expedite delivery. Specialized labels Notebook labels are mainly used for identifying the owner and purpose of the notebook. Some information on a label may include name, contents, and date started. Piggyback labels are made by combining two layers of adhesive substrate. The bottom layer forms the backing for the top. The label can be applied to any object as normal, the top layer can be a removable label that can be applied elsewhere, which may change the message or marking on the remaining label underneath. Often used on Express mail envelopes. Other applications include price change labels where when being scanned at the till, the till assistant can peel back the price-reduction label and scan the original barcode enabling stock flow management.