What was required to accept "troll"?

Solution 1:

Its earliest attestation appears to be from the early ‘90s, but its usage probably dates earlier:

Troll:

The internet sense (everyone seems to have his own definition of it) seems to date to the late 1980s or early 1990s and the Newsgroups era, and the verbal use is perhaps older than the noun. It seems to combine troll (v.) in the "fish with a moving line" sense (itself confused with trawl) and troll (n.1) "troublesome imp supposed to live underground."

(Etymonline)

The earliest known attestation according to the Oxford English Dictionary is in 1992.

The context of the quote cited in the Oxford English Dictionary[26] sets the origin in Usenet in the early 1990s as in the phrase "trolling for newbies", as used in alt.folklore.urban (AFU)

(Wikipedia)

Solution 2:

Eric Raymond, The New Hacker's Dictionary, third edition (1996) has the following entry for troll, covering its then-current meanings both as a verb and as a noun:

troll v.,n. {From the Usenet group alt.folklore.urban} To utter a posting on Usenet designed to attract predictable responses or flames. Derives from the phrase "trolling for newbies" which in turn comes from mainstream "trolling," a style of fishing in which one trails bait through a likely spot hoping for a bite. The well-constructed troll is a post that induces lot of newbies and flamers to make themselves look more clueless than they already do, while subtly conveying to the more savvy and experienced that it is in fact a deliberate troll. If you don't fall for the joke, you get to be in on it.

Some people claim that the troll is properly a narrower category than flame bait, that a troll is categorized by containing some assertion that is wrong but not overtly controversial.

This entry contains several interesting points. The first is the claim that the term derives from the earlier phrase "trolling for newbies," meaning that troll was probably a verb in Usenet-speak before it was a noun. The second is that even in 1996, the noun troll referred to the tactic of baiting newbies and flamers into overreacting to a post—not to the person responsible for creating the turmoil in a teapot. Third, Raymond evidently views trolling as an appropriate in-group exercise to expose respondents who are not in on the joke; there is no sense that a troll is anything other than a cheap good time to be had by the troller and the assembled cognoscenti.

The association of trolls with highly objectionable posters (rather than posts) that ruin civil online conversation by introducing irrational rants, needlessly offensive and inflammatory language, and a generally sophomoric idea of what constitutes good fun evidently came a bit later; but Raymond's description makes clear that the sophomoric element was there from the beginning—long before users began broadly associating "trolls" with misshapen fairy-tale creatures that live under stone bridges.

According to William Merrin, "President Troll: Trump, 4Chan and Memetic Warfare," in Catherine Happer, ‎Andrew Hoskins & ‎William Merrin, Trump's Media War (2019), the phrase arose in Usenet usage almost as soon as Usenet began to draw a critical mass of new users whom the old-timers could look down on:

'Trolling' later became a fishing term, referring to the dragging of baited line behind a boat to see what could be caught, and it was this meaning that survived through to the Vietnam War where US pilots described 'trolling for MiGs'—trying to draw out enemy aircraft, often as a decoy for other activity [citation omitted]. It was these ideas, of sport and baiting and drawing out and playing with the target that inspired the early online use of the term. An influx of new Usenet users in 1992 caused irritation for established members and 'trolling for newbies'—trying to provoke a response that could be mocked— became a recognizable activity [citation omitted]. Online trolling would develop in the following years but one of its defining elements would remain that of sport—of the pleasure of playing with and catching someone. But the Usenet example also highlights another defining aspect of trolling, as they mocked the newbies not because they were new, but because they affected authority. Trolling, therefore, is a baiting, a sport, a playing, that more than anything aims at those who get above themselves, or set themselves above others—at those asserting, or in, authority.

But eventually, as the Internet became a mass medium, troll ceased to be understood by most of its longtime users to refer to a faux controversial posting intended to rile up and expose clueless newcomers and became instead a term for a boorish troublemaker—an ignorant or zealous saboteur who tried to ruin useful online discussions purely for personal enjoyment—and the catch-phrase among veteran participants of a site was no longer "trolling for newbies" but "don't feed the trolls."

Solution 3:

Customarily, a word enters a dictionary when the lexicographers involved deem the word to have met their dictionary's criteria for inclusion. These standards can change from dictionary to dictionary, but the Oxford English Dictionary's explanation is pretty typical:

The OED requires several independent examples of the word being used, and also evidence that the word has been in use for a reasonable amount of time. The exact time-span and number of examples may vary: for instance, one word may be included on the evidence of only a few examples, spread out over a long period of time, while another may gather momentum very quickly, resulting in a wide range of evidence in a shorter space of time. We also look for the word to reach a level of general currency where it is unselfconsciously used with the expectation of being understood: that is, we look for examples of uses of a word that are not immediately followed by an explanation of its meaning for the benefit of the reader. We have a large range of words under constant review, and as items are assessed for inclusion in the dictionary, words which have not yet accumulated enough evidence are kept on file, so that we can refer back to them if further evidence comes to light.

Professional and amateur researchers regularly send leads into the OED, which are reviewed by dictionary staff. Many dictionaries also have staff who do research on new words and collect examples themselves. Sometimes they even get together to discuss their work at conferences. It can take some lead time for a word to qualify, or for enough samples to be collected so that a word qualifies.

When did troll meet dictionary standards? The word, even as a verb, was around for a long time. The digital version came about in the 1990s and 2000s. Its date of inclusion in a dictionary would vary:

• OED: Verb and noun added March 2006; earliest example from 1992.
• Merriam-Webster: Not present in 2009 entry (Wayback) and not present as late as 2016 (Wayback), though it's present today.
• American Heritage: Present at least from 2016. My fourth edition copy (from 2001) does not have it.

A decade gap seems pretty typical for digital usage from the late 1980s and early 1990s. Since then, as Merriam-Webster's editors acknowledge, the pace for incorporating words from the internet has sped up because editors have lots of tools for collecting examples of usage. That's why (again explained by Merriam-Webster) dox could take only six years to enter the M-W dictionary from its first recorded use in 2009 to entry into Merriam-Webster in 2015, at a moment when the word exploded into common usage.