Peter MacNicol was an Emmy nominee for a fleeting six days. Last week, the Television Academy revoked his comedy guest actor nomination for playing Jeff Kane on Veep after it was brought to attention that MacNicol was in too many episodes to qualify as a guest star. Girls' Peter Scolari was the replacement nominee.

MacNicol, who won an Emmy for Ally McBeal, handled it all with class, congratulating Scolari on Twitter and replying to a disappointed fan that he's grateful HBO submitted him in the first place. But the whole thing is kind of embarrassing for the TV Academy. This is the second time a contender was discovered to be void this year: Jason Sudeikis was removed from the comedy guest actor ballot during nomination voting because he was in too many episodes of The Last Man on Earth. Leaving aside the fact that the academy should be vetting these things that are so easy to vet, the question is something that has long plagued the Emmys: What determines a guest performance?

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The Emmys has played so fast and loose when it comes to guest contenders over the years that you'll be permanently side-eyeing them after you learn exactly what a clusterf--- it used to be. Since last year, you have to appear in less than 50 percent of a show's season to qualify as a guest performer, otherwise you'll have to try your luck in supporting. MacNicol, who was submitted by HBO before Veep's season was completed, appeared in five of the 10 episodes, and his offending episode — the penultimate one of the season — features him for 10 seconds. Sudeikis appeared in 11 of Last Man's 18 episodes. That sounds fair, right? Historically, though, the Emmys' treatment of guest stars has been totally nonsensical.

Timothy Simons, Reid Scott, Peter MacNicol, VeepTimothy Simons, Reid Scott, Peter MacNicol, Veep

Before the guest categories were established in the '80s, single and guest performers were allowed to compete in lead and supporting races, which obviously is not fair at all, but you can perhaps chalk it up to the youth and naivete of the early days, not to mention the fluidity of TV back then. That, however, didn't stop voters from giving the comedy lead actress Emmy to Ruth Gordon for her one-episode appearance on Taxi in 1979 over All in the Family's Jean Stapleton and The Jeffersons' Isabel Sanford.

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In 1986, the guest categories were established and were unisex until 1989. The guest awards, as they still are, were handed out on the Creative Arts ceremony, and a bunch of fragile egos were bruised in 1991 over the guest actors' absence on the main show. So, in 1992, the guest categories were eliminated, and guest stars were stupidly allowed to compete in the supporting and lead categories. That begot completely absurd lineups, like Ted Danson, who was in 26 episodes of Cheers that year, competing against Kelsey Grammer, who appeared in one episode of Wings as Frasier Crane, for comedy lead actor. Even more mind-boggling, Grammer wasn't nominated in supporting for his series regular role as Frasier on Cheers.

Worse, Christopher Lloyd won drama lead actor for his one-episode appearance on Road to Avonlea, beating full-season work from Sam Waterston on I'll Fly Away, Scott Bakula on Quantum Leap and Rob Morror on Northern Exposure. Oh, and one-episode appearances by Kirk Douglas on Tales From the Crypt and Harrison Page on Quantum Leap too. Totally level playing field, no? Northern Exposure's Valerie Mahaffey also won drama supporting actress for her three-episode stint over series regular Cynthia Geary.

After another revolt, the guest races were reinstated for 1993, with the compromise for the guest winners to present on the main show. (Actors, amirite?)

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Under those rules, which, again, were in effect until last year, you could compete in guest with a mere guest star credit. Eventually, this led to shows/networks/actors taking advantage of that technicality, and you got the opposite effect: Actors who were "guest stars" in name only competing — and winning — in the guest races for what were basically regular supporting or lead roles.

John Lithgow appeared in all 12 episodes of Season 4 of Dexter and won drama guest actor in 2010. Uzo Aduba appeared in 11 of 13 episodes of Orange Is the New Black's first season and won comedy guest actress in 2014. In fact, three of the four guest winners in 2014 would be ineligible under the current rule: Joe Morton (Scandal) and Allison Janney (Masters of Sex) also appeared in more than half of their shows' respective seasons, and both had major, long-running storylines that a mere guest star would not have.

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The new rule was instituted to curb this type of category fraud. But is this the best way to determine a guest performer? I do believe a hard regulation is necessary, since, clearly, people would've continued to (legally) abuse the old rule. But should guests be determined by episode count? Percentage of screen time throughout the season? Minutes of screen time? By his count, MacNicol appeared in a mere nine minutes of Veep last season. And if you watched Veep, you would never consider Jeff Kane's pop-ins and non-continuous arcs as a regular supporting part.

I don't know if there is a correct answer, and every case is arguably subjective. But I think the current rule would be improved with two tweaks. First, make it "50 percent or less." It's tougher for shows with even-numbered episodes in a season, like Veep, at "less than 50 percent." Second, allow an appeal process. Just like how shows can appeal their genre status (hour-long Shameless was approved to compete in comedy instead of drama; Orange's request for the same switch was denied last year), let actors with borderline cases like MacNicol appeal. Maybe he'd still be a nominee right now.

And please, have someone vet submissions while you're at it, guys.

The 68th Primetime Emmy Awards, hosted by Jimmy Kimmel, will air Sunday, Sept. 18 at 8 p.m. ET / 5 p.m. PT on ABC.