Definitions and usages
HTML tags are used to set the default font size for documents.
You can make changes relative to the default font size using
Instructions for use:
Don't use this label again! Although it has been (not strictly) standardized in HTML 3.2, it is not supported by mainstream browsers.
Moreover, different browsers, or even adjacent versions of the same browser, do not use the same implementation;
The difference between HTML 4.01 and HTML 5
HTML 5 does not support labeling. Use CSS instead.