[gaugefield]

There is a convention in academic papers where you write the explanation for the 1st occurrence of the abbreviation, then leave it out for the rest of the paper. I suggest others to follow the same, except maybe for the most obvious ones (like HTML mentioned in the other reply)

[diggan]

> HTML

Did you mean Hypertext Markup Language (HTML)?

It's a trite comment to make (the original complaint). Don't know an abbreviation? Takes two seconds to look it up. Not all content on the web is written for the lowest common denominator, and thank god for that.

[bluGill]

Content should be written for the lowest common denominator of your target audience. If you are writing for someone who writes web documents all day then you can expect them to know what html is in great detail. If you write for plumbers they might not know what html is, and so you may need a couple paragraphs to define what it is. (I'm not sure why plumbers would need to know what a html tag is, but if you expect them to read a document where html tags are referred to you better define html in enough detail that they understand it)

[codydkdc]

this is a general convention in technical documentation as well