The Universal Product Code is a barcode symbology that is widely used worldwide for tracking trade items in stores.
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The XLTM file extension represents files that are generated by Microsoft Excel as Macro-enabled template files. XLTM files are similar to XLTX in structure other than that the later doesn't support creating template files with macros. Such template files are used to generate and set the layout, formatting, and other settings along with the macros to facilitate creating similar XLSX files then.
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You can also sign other file formats. Please see the list below.