Academic classes

When you go to submit a paper, you are often told to use not article but some unfamiliar class name — IEEEtran, acmart, llncs, elsarticle, or revtex4-2. These are document classes shipped by the society or publisher itself: the class enforces that venue’s rules for column layout, margins, headings, and even the bibliography style. This page walks through the major classes a researcher meets, each in terms of who it is for, where to get it, and the quirks of its own command set.

The pattern: a venue ships a class

Before learning each one individually, it helps to see the pattern they all share. The venue — a society, a publisher, a conference — distributes a bundle: a **class file (.cls), a matching bibliography style (.bst), and a fill-in-the-blanks template**. You download that template and pour your manuscript into it. The class takes care of layout, so you never decide whether to use two columns, what the margins are, or how headings are set — and in fact you are usually forbidden from changing them.

This is where LaTeX’s core idea — separating logical structure from appearance — pays off in practice. Write only meaning in the body (\section{...}, \cite{...}), and the same manuscript can be re-set in another society’s style simply by switching classes. The key caveat: class versions change over time. Always fetch the current template from the venue’s author kit (author center) rather than reusing an old local copy. Layout breaking from a version mismatch right before a deadline is a common mishap.

One more practical note: these classes are usually not present in a minimal TeX install. A full TeX Live or MiKTeX install bundles IEEEtran, acmart, elsarticle, revtex, and others, but on a minimal setup you install them individually (e.g. tlmgr install IEEEtran) or download the .cls from the publisher and drop it next to your manuscript (llncs in particular is often placed locally). They are all on CTAN too, so installing through your distribution’s package manager is the reliable route.

IEEEtran — IEEE journals & conferences

IEEEtran is the class for the transactions, journals, and international conferences of the IEEE, the largest body in electrical, electronic, and information engineering. Its defining trait is that you select the mode through a bracketed option, not the main argument: \documentclass[journal]{IEEEtran} gives a two-column journal, while \documentclass[conference]{IEEEtran} gives the conference-proceedings layout. There is also technote for brief notes and peerreview for review copies, and you can combine a font size and the Computer Society option, as in \documentclass[10pt,journal,compsoc]{IEEEtran}.

As for its own conventions, the summary goes in an abstract environment and the keywords in a dedicated **IEEEkeywords environment — which is automatically titled “Index Terms” in journal mode and “Keywords” in conference mode. For references, the standard BibTeX style is IEEEtran.bst. Templates are distributed through the IEEE Template Selector** (template-selector.ieee.org), which always carries the current version; fetch yours from there first.

\documentclass[conference]{IEEEtran}
\begin{document}
\title{A Conference Paper}
\author{\IEEEauthorblockN{Ada Lovelace}
  \IEEEauthorblockA{Analytical Engine Lab\\ London, UK}}
\maketitle

\begin{abstract}
This is the abstract.
\end{abstract}

\begin{IEEEkeywords}
broadband networks, quality of service
\end{IEEEkeywords}

\section{Introduction}
IEEE recommends composing in the two-column format.
\end{document}

acmart — ACM journals & proceedings

acmart is the consolidated class distributed by the ACM in computer science; it replaced the older, fragmented set of per-conference and per-journal classes. You normally **choose the look through the format= option** (the format= part may be omitted). For review submissions use the default **manuscript (single column); most journals use acmsmall; conference proceedings use sigconf; SIGPLAN venues use sigplan**. So you write, for example, \documentclass[sigconf]{acmart} or \documentclass[manuscript,review]{acmart}.

A rule of thumb for telling them apart: **formats starting with acm are for journals, transactions, and course material, while those starting with sig are for proceedings published as books.** In journals you set the title with a short name, e.g. \acmJournal{TOMS}. As for its conventions, you declare CCS (ACM Computing Classification System) concepts with \begin{CCSXML}...\end{CCSXML} and \ccsdesc{...}, alongside \keywords{...}; these are required for regular papers. References use **ACM-Reference-Format** (natbib-based), which produces ACM’s own citation style. Note that the SIGCHI sigchi/sigchi-a formats were retired in 2020 and are now folded into sigconf.

Internally acmart loads amsart, so the AMS theorem environments and the like are available. One thing to watch: the ACM template assumes specific fonts such as libertine, and compilation can fail if they are not installed. Substituting fonts or altering the margins is not permitted.

\documentclass[sigconf]{acmart}
\begin{document}
\title{A Proceedings Paper}
\author{Ada Lovelace}
\affiliation{\institution{Analytical Engine Lab}\city{London}\country{UK}}

\begin{abstract}
This is the abstract.
\end{abstract}

\ccsdesc[500]{Networks~Network reliability}
\keywords{broadband networks, quality of service}
\maketitle

\section{Introduction}
The \texttt{sigconf} format sets the ACM proceedings layout.
\end{document}

llncs — Springer LNCS

llncs is the class for Springer’s proceedings series Lecture Notes in Computer Science (LNCS) and its siblings LNAI (artificial intelligence) and LNBI (bioinformatics). A great many international conferences that publish proceedings through Springer — ECCV, MICCAI, and hundreds of others — use this layout. You select it by class name, \documentclass{llncs}, and it gives a single-column layout extending article.

Its conventions are in how authors and affiliations are written. The class adds an **\institute command** not present in standard LaTeX: you attach an affiliation number to each author with \inst{n}, as in \author{Ivar Ekeland\inst{1} \and Roger Temam\inst{2}}, and list the affiliations with \institute{first affiliation \and second affiliation}. The email address goes **inside \institute as \email{...}**. The summary uses the abstract environment. Multiple affiliations are separated by \and and numbered automatically. The current standard bibliography style is **splncs04** (\bibliographystyle{splncs04}). The runningheads option is for volume editors and is usually unnecessary for a single submission.

\documentclass{llncs}
\begin{document}
\title{An LNCS Contribution}
\author{Ivar Ekeland\inst{1} \and Roger Temam\inst{2}}
\institute{Paris-Dauphine University, Paris, France\\
  \email{[email protected]}
  \and Sorbonne University, Paris, France\\
  \email{[email protected]}}
\maketitle

\begin{abstract}
The abstract follows the title block.
\end{abstract}

\section{Introduction}
llncs extends \texttt{article} with \texttt{\textbackslash institute}.
\end{document}

elsarticle — Elsevier journals

elsarticle is the class for manuscripts submitted to Elsevier journals. You use it as \documentclass[preprint,12pt]{elsarticle}; its default options are a4paper,10pt,oneside,onecolumn,preprint. preprint gives the roomy single-column preprint look used for submission, while the final two-column journal layout is set by the publisher (you can also use review for wide-spaced review copy or final for something close to the printed look). All of article’s options remain available.

Its conventions center on the **frontmatter environment.** The title \title{...}, authors \author{...}, and affiliations \affiliation{...} go inside it; the summary uses an abstract environment and keywords a keyword environment. There are two ways to tie authors to affiliations: one links each author to an affiliation with a footnote marker, the other groups authors of the same affiliation together with the affiliation following. For references you pick the numeric **elsarticle-num, the author–year elsarticle-harv**, or the natbib-extended elsarticle-num-names. The class is still actively updated (recent releases are in the 3.x line), so check for the latest before submitting.

\documentclass[preprint,12pt]{elsarticle}
\begin{document}
\begin{frontmatter}
\title{An Elsevier Manuscript}
\author{Ada Lovelace}
\affiliation{organization={Analytical Engine Lab},
  city={London}, country={UK}}

\begin{abstract}
The abstract lives inside the front matter.
\end{abstract}

\begin{keyword}
broadband networks \sep quality of service
\end{keyword}
\end{frontmatter}

\section{Introduction}
\bibliographystyle{elsarticle-num}
\end{document}

REVTeX — physics (APS / AIP)

REVTeX is the class for the journals of the APS (American Physical Society) and AIP (American Institute of Physics); the current release is **revtex4-2** (the class name itself carries the version). It is used by the major physics journals such as Physical Review Letters (PRL) and Physical Review B (PRD/PRB). You select the publisher with the aps / aip option and can also name the journal directly: \documentclass[prl,aps]{revtex4-2} gives the PRL layout, \documentclass[prb,aps]{revtex4-2} the PRB layout (there are many journal options — prx, prfluids, and more).

As for its conventions, authors and affiliations work by **placing \affiliation{...} directly after each \author{...}**; consecutive authors sharing an affiliation are collated automatically and given superscript affiliation numbers. The reprint option gives a two-column preview close to the printed look, and there are many layout options like twocolumn, preprint, and superscriptaddress. REVTeX requires natbib and sets references with styles such as apsrev4-2 (numeric). Templates come from the APS REVTeX page and are also on CTAN as revtex.

\documentclass[prl,aps,reprint]{revtex4-2}
\begin{document}
\title{A Physical Review Letter}
\author{Ada Lovelace}
\affiliation{Analytical Engine Lab, London, UK}
\author{Charles Babbage}
\affiliation{Analytical Engine Lab, London, UK}

\begin{abstract}
The abstract precedes \textbackslash maketitle output here.
\end{abstract}
\maketitle

\section{Introduction}
Each \texttt{\textbackslash author} is followed by its \texttt{\textbackslash affiliation}.
\end{document}

Compared at a glance

Laying the major classes side by side, by venue and the thing worth remembering, gives the following. They share one premise: each is specific to its venue, not a general-purpose class whose layout you freely tweak.

These are only representative examples. Springer also has a newer consolidated class sn-jnl, mathematics has the AMS amsart, and countless other classes and templates exist per society and university. The drill is the same in every case — start from the venue’s author kit and pull the current template, class, and bibliography style as a set.

Practical tips

• Get the whole template, not just the class. The fastest path is to download the venue’s bundle — the filled-in skeleton (.tex), the .bst, and sample figures/tables — rather than the class file alone.
• Check for the latest version. Classes get revised; use the current release from the author center, not an old local copy.
• Install separately on a minimal setup. A full install bundles them, but on a minimal environment install via tlmgr (etc.) or drop the .cls next to your manuscript.
• Do not rewrite the layout. Changing margins, columns, or fonts usually violates the submission rules; tune only within the options the class provides.
• Use the matching bibliography style. Pick the .bst or biblatex style that ships with the class — IEEEtran.bst, ACM-Reference-Format, splncs04, elsarticle-num, apsrev4-2, and so on.
• Submission and final options can differ. Switch options by stage — acmart’s manuscript/review, elsarticle’s preprint/final, and the like.