ASCII tab is a text file format used for writing guitar, bass guitar and drum tabulatures (a form of musical notation) that uses plain ASCII numbers, letters and symbols. It is the only widespread file format for representing tabulature, and is extensively used for disseminating tabulature via the Internet. There are various computer programs for creating guitar tabulature which can save ASCII tab files, but due to the unpredictability of the format, only a few (e.g. G7) can read arbitrary ASCII tab files created by humans.