An attractive document contains well structured and sensibly formatted sentences, paragraphs, tables, and other elements. To create a document in a computer, we type words, characters, punctuation and other symbols in an electronic file, and then insert tags implementing formatting. In practice, most documents are created using advanced word editing programs (applications). Formatting is typically enforced by selecting (highlighting) text with the computer mouse and then clicking on embellishing buttons to underline, set in bold face, change the font size, or implement a wide range of other features offered in menus. The application automatically generates formatting tags that are implicitly contained in the document but are not displayed on the computer screen, unless optionally requested.