Keywords are used to narrow a search in an algorithm when locating datawords on a page. The most common KeyWords are preprinted literals that appear on the form. When searching for a particular piece of data, first search for the KeyWord and then attempt to find the data by using its relative location and distance to the various tokens on the form.
For example, to find an invoice number, the keyword might be "Invoice Number" and the dataword would be "IN-1234".