Tutorial 16: Client-Side Scripting 101 - HTML with Style | 6
Other script might do things that are not related to the document itself, such as set up event handling. If a SCRIPT element has the DEFER attribute, it indicates that the script contained or linked in that element does not have to be executed immediately. Although this is a nice addition to HTML 4.0, to my knowledge it is as yet unsupported by any browser. However, if you insert scripts that can be executed later on while the rest of the document is rendered, use this attribute, since it has no adverse effects.
Produced by Stephanos Piperoglou
Created: September 15, 1999
Revised: September 27, 1999