I have just been reading a rather heated discussion here (now closed). People used abbreviations a few times with no explanation of what they meant.
One thing that I do remember from my abysmal education was that when using abbreviations, using the abbreviation for the first time, write the full meaning in brackets after it.
It is only required to do so on the first use of the abbreviation. After that the abbreviation on its own is quite acceptable.
I am not really worried if it is the correct method of doing things, but it certainly makes life easier for the person reading the article.