First Take: In the general sense, annotation refers to a “note” or comment that is used to clarify or provide background on a main text.
Deeper: Annotations have a much more complicated role in works of journalism that is generally recognized or theorized. Because daily reporters often “embed” attribution in their story-telling–that is, because they say something like “When I spoke to the general, he said…”–reporters don’t feel a need to offer further documentation or context in such a moment. Moreover, especially when the story being told is relying on direct witnessing, you’ll find long-form journalists never bothering to say where or when they heard something, or provide contextual documentation for it, in what we’re reading. That’s because they’re usually implying that if you don’t see a source directly annotated, then (a) it’s because it was directly witnessed or (b) the journalist could provide the source if asked (e.g. notes are back at the editor’s office). This can seem contradictory, but it’s important: “fact-checking” doesn’t mean the source will be documented in every instance: it just means “if we had to, we could.” Thus long-form journalists have more liberty in regard to attribution than daily reporters do. In other words, though we think long-form writing is about “elaboration,” that’s not entirely the case.
The other element that makes annotation (or the lack of it) interesting is that reporters are quite often writing in the heat of a larger “news event,” and quite often, they simply assume that the reader knows the broader frameworks of what they’re talking about. So, if you’re in Vietnam in the mid-1960s, and you refer to “William Westmoreland,” you don’t pause to tell your reader who he is (the commander of US forces at the time) because, at the time, it would be like saying “Vietnam is a country in Southeast Asia.”
Unfortunately, however, these practices can affect the longevity of a given work of reportage. That is, an an undue lack of annotation often makes it hard for readers in subsequent generations to really know the context a journalist was referring to. It can seem, unfortunately, that–say, unlike many a novel–many works of narrative journalism are only written for their own historical moment. It can also mean that such works have “constructed” a knowing audience that, over time, will disappear. One wonders, then, if this means their work will also lose readership generally.