Found a couple of references although different countries may have different guidelines
Source A - US Rules
The ampersand (e.g. “Al Gough & Miles Millar”) means that the two writers are a team, and are treated as one person for WGA purposes.
The other version (e.g. “Josh Friedman and David Koepp”) indicates that the writers worked at different times. In ...
Legal/contractual obligations to list all staff who've worked on film
Evidence that staff have worked on film, which can be used to help them gain future employment
Some movie-goers are extremely interested in credits and finding out who was responsible for what
E! Online were asked a question about why ...
Monty Python's Flying Circus did this. According to TV Tropes:
Credits Gag: In addition to many Creative Closing Credits, the placement of the credits in the show's sequence was a gag in itself.
Of particular note is the episode "The Golden Age of Ballooning", where the closing credits ran about halfway through the show.
The next episode, "...
From forbes by Carol Pinchefsky,
Note: I had wondered if Dinklage’s Outstanding Supporting Actor Emmy award had anything to do with the position of his name on the credits. However, Elizabeth Moseley, the director of Theatrical & Television Contracts at SAG-AFTRA, told me that an award doesn’t guarantee top billing. Moseley said the credits are “...
These are joke credits deliberately placed by the director Stephen Soderbergh.
“Introducing” Julia Roberts
Soderbergh: She was the only person we had in mind. We thought it would be fun for her to be the only woman. We sent her the script with $20 enclosed and a note saying, “We hear you get 20 for a picture”.
Clooney: She kept the 20. We deducted it from ...
Because it's not necessary
Whilst it would have been nice, the original novel was published in 1897 and the usual copyright / rights period is, depending on location from 50 - 70 years after the author's death.
So there are no payments to be made to anyone nor is permission needed to use the title so there is no particular need to credit the author.
According to David Feldman's book Imponderables: The Solution to the Mysteries of Everyday Life:
Why are copyrighted dates on movies and television shows written in Roman numerals?
The general consensus is the "deception theory":
to "make it difficult for viewers to determine exactly how old the show is", the reason being the older the ...
From this question & answer at Science Fiction & Fantasy
What’s with the clanks at the end of the credits in Avengers: Endgame?
According to Vanity Fair Disney have confirmed....
There is no traditional Marvel end-of-credits scene or teaser in Avengers: Endgame—but there is a little treat for patient fans who sat through the movie’s very, very, ...
Hugh Laurie has been well known in the UK since the 1980s, appearing in such popular TV shows as:
The Young Ones
A Bit of Fry and Laurie
Blackadder (series 2 - 4)
Jeeves and Wooster
And parts in the films:
Before 1998 when these episodes were made.
As these episodes were set in the UK, a well known (and ...
There are a lot of films with actors/actresses who dominate the film, but actually have very little screen time. For example, Orson Welles in The Third Man had ~10 minutes of screen time. Heath Ledger in The Dark Knight had just under 20 minutes. Judi Dench won an Oscar for Shakespeare in Love for less than 8 minutes acting time. Similarly, Beatrice Straight ...
It's actually an initial on her letterman sweater. Sabrina attends Baxter High School.
Sabrina Spellman, a teenage half-witch who lives in the town of
Greendale with her aunts, her cousin Ambrose, and her familiar Salem.
Unbeknownst to Sabrina, when she was just a year old, she was taken
from her mother, Diana, by her aunts with the approval of her ...
EDIT: We might have a new record. In the US historical epic One Night with the King from 2006, Peter O'Toole briefly appears in the prologue as the Prophet Samuel for "barely 30 seconds", according to Leonard Maltin's 2015 Movie Guide. (I timed it myself and it's about 25 seconds). Despite this, he's top-billed as the film's star:
Another notable example ...
I believe the notorious film Irréversible does this as part of its "reverse chronology" gimmick. The credits roll right at the very beginning, reversed so they scroll from top-to-bottom instead of bottom-to-top.
Even though it doesn't count, as it's not a movie or TV show, I feel obliged to mention Donkey Kong Country. You defeat King K. Rool, a fake set of ...
There are two reasons to include someone in the credits:
Since H.G. Wells's copyright has expired, there was no licensing contract between the studio and his estate for rights to make the movie--a contract that likely would have required the studio to credit Wells. Since titles alone (at least in the U.S.) are not subject to ...
In addition to the legal reasons, let's consider two old movies with old source material
1931's Dracula was so successful, it spawned multiple Dracula/vampire stories not written by Stoker (and Bella Lugosi got typecast as a result). Sadly, it was a movie based on a play based on the book, which is part of why it eventually spawned a whole ...
The very-first end-credit scene was apparently from The Silencers movie which was released in the year 1966 based on this article
The first modern post-credits scene seems to be the tag at the end of The Silencers, a 1966 James Bond spoof starring Dean Martin, according to the site What's After the Credits? The scene in question parodied the familiar James ...
A lot of this will be defining terms.
Prior to the advent of computer animation, animation meant taking a bunch of still photos that had slight changes from one photo to the next and then playing those photos back fast enough to create the illusion of smooth motion. When doing animation this way, it's critically important to control every ...
This is because there is a difference between how IMDb (or another source) lists the actor's name than their credit in a movie. The name after 'as' shows how they were credited in the movie.
In the case here, it is because there is a difference in the capitalization between Dane DeHaan and Dane Dehaan. The difference here is relatively minor, they can be ...
From the IMDB trivia page
James Earl Jones supplied the voice of Darth Vader, but specifically requested that he not be credited. At the time, the reason he cited was that he felt he had not done enough work to get the billing, but he later admitted that he didn't want his name associated with the film because he was still an up-and-coming actor, and didn'...
Same reason everything else about their credits is formatted as it is: their contracts said so.
In the specific case of EPs, there's really three different "kinds" of executive producer for a TV show (with movies it's slightly different):
Some executive producers are credited because they own the rights to intellectual property that requires they be given ...
My best answer comes from an answer that was given to this same question in 2006:
Adult Myers is introduced in the screenplay as a shape jumping on the
back of Marion's car. Therefore, for script consistency, the term was
used for the rest of the draft and eventually the series.
Also, there is further explanation and links to the script here.
The Screen Actor's Guild sets certain required pay scales for actors. In some cases actors will agree to pay adjustments or a lack of credit as a favor to a friend directing the film (Robin Williams in Baron Munchausen) or just to have the chance to cameo in the film for fun. In some cases an actor won't be billed so as not to spoil a surprise. Lately the ...
In this case Time which equals money.
The vast majority of TV content is still provided by TV networks who make their income from ads. Every second not devoted to actual content is a second they can't sell.
Now, the credits in TV are usually down to union rules/contracts and what can be negotiated by the producers.
Chuck Lorre is famous for having a ...
Because the producers saw the potential for a "will they, won't they"-relationship. Quoting Wikipedia:
The chemistry between Janel Moloney and Bradley Whitford, who
portrayed Josh Lyman, caught producers' attention early in the series.
After seeing Moloney and Whitford perform together in the pilot, Aaron
Sorkin added a scene in which Donna argues ...
I believe this is due to what TV Tropes calls a "Small Reference Pool" - pop culture's understanding of a topic only goes so far. Top Gear always uses these gag credits during its foreign specials, using either the names of famous people from that region, or a name commonly associated with that region ("Billy Bob", during the infamous USA special).
But how ...
According to an article about the credits for the movie at TrekMovie.com,
although they [Hemsworth and Morrison] don’t appear in the film, some of their dialog from the 2009 movie can be briefly heard during a dream sequence/flashback.
Presumably that counts as a speaking part, so they have to be in the credits.
There's a bit of prestige being listed last. Generally this spot is for a famous actor that has a small role. For the Hobbit movies, Bloom isn't in all the films so he won't get the same type of billing as the regular players. The SAG rules are different for guest stars and featured players than for principal players. For Andy Serkis, I think it's because he'...
In the early days of Hollywood, at the Academy awards, the Academy members could choose whether they thought an actor’s performance was leading or supporting.
This led to an interesting scenario in 1945, where an actor was nominated for the leading and supporting Oscars for the exact same role (Going My Way).
After this the Academy changed the rulings and ...
Generally, these abbreviations you see indicate a society or union that person is a member of. Since such societies are very distinctive and respected ones, people add it to their names in credits. Just like when one has Ph.D. degree, he/she would prefix Dr. or suffix Ph.D. in his/her name.
It stands for American Cinema Editors, a society for ...