Text Attribute Tags
For the most part, HTML tags are intended to be used to indicate the function that a particular piece of text serves within the document, rather than actually specifying how the text should be displayed. That decision is normally left up to the browser (and sometimes also to the preferences that the user has specified).
So, for example, you would expect there to be a tag to indicate that a particular bit of text was a Chapter Title, but this wouldn't specify exactly what a Chapter Title should look like. This is something you need to get used to as an HTML author--many of the decisions about exactly how your document looks aren't really up to you. Instead, they're in the hands of the person who is reading your document (or determined by the limitations or features of the browser that that person is using).
Nevertheless, there are a number of tags that reflect a difference in the purpose of a piece of text by changing how that text is displayed. These are the text attribute tags.
In keeping with the philosophy of specifying function, rather than form, there are two tags that are used to indicate emphasis. These are the EM-tag, for normal emphasis, and the STRONG-tag, for even more emphasis. Both are paired tags. The effect they have is as follows:
- The HTML source:
- This is <EM>emphatic</EM> and this is <STRONG>even more emphatic.</STRONG>
- The result:
- This is emphatic and this is even more emphatic.
There are times when you might want to exert more explicit control over how an item gets displayed. For these times, there are tags that you can use. The B-tag specifies boldface, the I-tag specifies italics. Of course, some browsers (such as Lynx) may not be able to display these, and so might still interpret them in another way. (On my PC, normal text is displayed in white on a black background; Lynx displays both bold and italics, as well as emphasized and strongly-emphasized text, as red text on a black background.) The B and I tags are both paired tags.
The final text attribute tags that we will discuss in this seminar (there are others) are the heading tags. These are used to indicate the start of a new part (logically) of a document. There are different levels of heading, corresponding to the different levels of document structure. Rather than assume any particular structure on your part, the levels are simply numbered, and you may use them as you wish. The tags are H1, H2, H3, and so on. These are all paired tags.
For example, you might decide that level 1, the topmost level, should correspond to the "document" level; that is, that each different document you create will have a level 1 heading at the top. You might then decide that level 2 would correspond to chapter titles, level 3 would correspond to section headings, and level 4 to subsections. There are a total of 6 heading levels, but you don't have to use them all.
For most browsers, the effect that heading level has on the text is that the size changes (level 1 is the largest); headings might also be bolder than normal text. Keep in mind, though, that changing the text size is not the purpose of headings; it is simply the way they are most often expressed. The purpose is to clarify the different levels of structure within your document.
SDR, 11 Jun 1995.