Using definite article before abbreviations

1

Consider this part of a technical article.

Approaches to boilerplate detection typically exploit DOM- level features of segments by means of handcrafted rules or trained classifiers, or they identify common, i.e., frequently used segments or patterns/shingles on a website ..... Yi et al. simplify the DOM structure by deriving a so-called Site Style Tree which is then used for classification [26]. Baluja [2] employs decision tree learning and entropy reduction for template detection at DOM level.

DOM is abbreviation for Document Object Model, in this article sometimes it is used with "the" and sometimes without it, Why? As I checked another document, they may use the DOM tree but DOM trees.

I guess as the DOM tree and the DOM structure is unique, they use "the"

In general, are there rules for definite article and abbreviations?

1

In general treat the abbreviation as if it were expanded, and act accordingly.

It is not because the DOM tree is unique that the definite article is used, but because it is a specific tree, the tree of the Document Object Model.

In DOM trees the plural refers to the noun generically/collectively.

The Asian elephant has smaller ears than the African elephant.

Asian elephants have smaller ears than African elephants.

Chrysler engines are often a little larger|smaller than those of their competitors.

I always was doubtful where the may be used before a N + N construction, once I thought even A + N get articles like the red color, but they said no it could be "red color". Here DOM seems like an attribute or it is a specific N+N construction which needs the?! – Ahmad – 2015-08-11T17:22:34.307

The acronym is used attributively. The DOM tree. – Tᴚoɯɐuo – 2015-08-11T17:26:01.383

So the DOM tree but not the red color? Why? – Ahmad – 2015-08-11T17:30:57.263

Try searching for article with color here. I know the subject has come up many times. Also, CONTEXT IS EVERYTHING. You must use phrases in full sentences. – Tᴚoɯɐuo – 2015-08-11T18:28:51.630

I found some, but my question actually is if we use an adjective for a countable object so it makes it specific, then we use "the"? "the red color" or "red', means "the color that is red among colors". For example "the green continent" to mean the only continent which is green? – Ahmad – 2015-08-11T18:50:42.977

Ask this question separately. As I said, no fragments ("the green continent") only full sentences in your examples. – Tᴚoɯɐuo – 2015-08-11T19:20:02.937