This memo only describes the additions. Although it differs very little from the HTML 2.0 DTD, it is included in its entirety for ease of reference. Familiarity with HTML 2. 0 is assumed.
Tags mark the start and end of elements.
A piece of software that processes HTML 2.1 on behalf of a user. It may be a browser that displays formatted documents on screen, a dedicated editor, or any other software that acts on the specific information encoded in HTML 2.1. Tables are usually displayed with whitespace above and below to separate them from the previous and next paragraphs. The rules for determining how many columns a table has can be rather subtle, because cells can span several rows and columns. Section 6 contains an explanation of the layout algorithm.