hellsing

In the Hellsing series, most characters' names are written phonetically in Katakana to represent English names (except for Yumie), as Hellsing is set in Europe and features European characters. Due to this, it's quite hard to transliterate the characters' names back into the Latin alphabet. Even among official sources, spelling varies widely between different translations of the Hellsing anime, OVA and the Manga.

The Hellsing Wiki uses the Dark Horse translation for these characters' names, instead of the English dub of the OVA, for consistency. However, some exceptions have been made in cases where a name is written out fully in English in manga panels (such as "Hallconnen"). This page lists all other known variants of characters' names, from the original anime to the OVA and manga.

Hellsing Organisation

Alucard
Arucard: The name "Arucard" was used in Pioneer's merchandises of Hellsing. Alucard's name is written in Katakana as "アーカード," and pronounced as "Aakaado," however, when pronounced in a Japanese accent, it sounds like "Arucard." Netflix uses "Arucard" in their Japanese subtitles for Hellsing Ultimate. Oddly enough, they also have the Hellsing anime available to stream, and their subtitles for that series spell Alucard's name as "Alucard."
Arkard: Appeared in the original fan translation of the Hellsing manga by Hellsing Project. Specifically when Jan made fun of his name. Before the official English translation of the series, fans would often use "Arkard" too.
Sir Integral Fairbrook Wingates Hellsing
Integra: In the original manga and the one translated by Dark Horse Comics, "Integra" is used mainly as a nickname for Integral.
Integral Wingacy: Used in the original Hellsing Project scanlations.
Integral Van hellsing: Used in the original Hellsing Project scanlations.
Seras Victoria
Celes Victoria: Used in the original Hellsing Project scanlations.
Ceres Victoria: Before the Dark Horse Comics translation of the series, fans would constantly refer Seras as "Ceres."
Walter C. Dornez
Watson: Used in the original Hellsing Project scanlations.
Walter C. Ddollneazz: Used in the booklet of the Hellsing anime and the back cover of the original Japanese version of Volume 4.
Walter C. Dollneaz: Used in the ending credits of the tenth installment of the OVA.
Walter C. Dolneas: Used in the original Hellsing Project scanlations.
Pip Vernedead
Pip Bernadotte: Used in the ending credits of the tenth installment of the OVA. Also used in the original Hellsing Project scanlations. In addition, used in the booklet of the fifth volume of the OVA.
Bernadette: Used by DHC before they later changed it to "Vernedead." Possibly at the sight of Hirano writing "Pip Vern" in one of the chapter covers.
Abraham Van Helsing
He is never referred to as "Abraham" in the manga, OVA or anime. Instead, he's constantly referred to as "Former Sir Helsing," "Sir Helsing," and also sometimes, an added "L" in "Hellsing."

Iscariot Organization

Alexander Anderson
Alexander Andersen: Because of the katakana written for Anderson's name: "アレクサンド・アンデルセン." Anderson is usually spelled like "アンダーソン," in katakana, not "アンデルセン."
Arexandrawe Andersong: How Hirano spelled it in Chapter 5 of the first volume.
Heinkel Wulf
Heinkel Wolfe: Due to this name specifically appearing in the booklet of the fifth OVA, many fans adopted the name "Wolfe" as Heinkel's last name. Although DHC spelled it as "Wulf."
Renaldo

Renaldo's name originates from the original 2001 anime series. He's never referred to as such in the original manga or OVA, and is referred to as "father" in the ending credits.

Rinaldo: Used by fans of the series.
Ronaldo: Used in the subtitles of the anime.

Millennium Organization

The Major
Montiana Max: Appeared on one of the backgrounds in Volume 4; specifically the interrogation between Maxwell and a Bishop. Also appeared in the back cover of Volume 5 on The Major's handbook. It is considered to be The Major's official name.
Montana Max: Hellsing fans have adopted "Montana Max" as the Major's real name (including members of the OVA's English Dub cast), but as it has never been written in any of the dialogue, it is still considered unofficial.
The Captain
Hans Günsche: Bbecause of a scene where various names appeared in the background and Hans was one of them, many fans adopted the name "Hans Günsche" as The Captain's name.
Jan Valentine
Yan Valentine: Due to the pronunciation of "Jan." He is constantly referred to as "Yan" in the original anime, and also in the Japanese version of the OVA and anime. Also used in the ending credits of the tenth installment of the OVA, and the original scanlation of the Hellsing manga by the Hellsing Project.

Weapons

Casull
Joshua: Used in the original Hellsing Project. Since then, many fans have perpetuated the name, so much so that ADV (the Official European Distributor for the TV Series) called it "Joshua" on their Official Website, the Special Features, and the booklets on their DVD release.
Hellsing 13mm clockwork Giant PANDAS: Used in the cover of Volume 1.
Hallconnen
Harkonnen: Used in the English translation of the Hellsing manga by Dark Horse Comics, how the English dub pronounce the name of the weapon, and used in the original scanlation by Hellsing Project.