CSL 0.8.1 Syntax Overview
This page describes the syntax of version 0.8.1 of the Citation Style Language (CSL), including information specific to Zotero. An additional source of documentation is the CSL 0.8.1 schema, which is written in RELAX NG Compact and can be used for style validation.
Pointers on how CSL styles can be created, modified, validated, shared and installed in Zotero can be found here, together with more background information about CSL.
CSL Style Structure
All CSL styles share the same basic structure: only five different XML elements can be nested directly in the root element: , , , and . The roles of each of these elements (described in more detail below) are:
: contains metadata describing the style (name of the style, authors of the style, etc)
: describes how in-text citations should be formatted
: describes how bibliographies should be formatted
: allows for reuse of formatting instructions, allowing for more compact styles
: allows for the modification of locale-specific strings (e.g. “edited by” can be changed in “ed. by”)
Independent and Dependent Styles
Two main types of CSL styles exist: independent and dependent styles. An independent style contains a full style description, and includes at least the and element. Unless it is a note-based style that lacks a bibliography, it also includes the element. The element and one or more elements are optional in independent styles. A dependent style, on the other hand, merely refers to an independent style, like an alias or shortcut. It only includes the info element. Dependent styles are used if multiple publications share a single style format. Each publication can thus have its own dependent style (with the info section describing the journal's metadata, e.g. the journal's name or ISSNs) with a corresponding entry in (for instance) the Zotero Style Repository, while only a single independent master style has to be maintained.
Note that dependent styles cannot be used to indicate changes compared to the master style. If there is any difference in formatting between two styles, however small, two separate CSL styles have to be created.
Before the style element, each CSL style should include the XML declaration element, specifying the version of XML used as well as the character encoding. The element itself carries a number of arguments:
: the namespace declaration that binds the elements in the style to the given namespace URI
: with two possible values, “in-text” or “note”, this specifies whether the style is note-based or uses in-text citations coupled to a bibliography
(optional): specifies the locale used for argument values within the style
(optional): sets the localization of the style output. The effect is currently limited to localization of preset strings (e.g. “edited by”), but plans exist to extend this to punctuation (French quotes, different punctuation around quotation marks in American and British English). N.B. Support for the default-locale argument has not yet been implemented in Zotero. Currently styles are solely localized according to the locale set in Firefox, which can be overruled with the export.bibliographyLocale user preference.
An example of a preamble is shown below. For most styles only the value of and will differ.<?xmlversion="1.0"encoding="UTF-8"?><stylexmlns="http://purl.org/net/xbiblio/csl"class="in-text"xml:lang="en"default-locale="fr-FR">
The section of a CSL style contains the style metadata, which does not affect the formatting of citations. Instead, the metadata makes it possible to host styles in style repositories, to allow users to subscribe to field-specific style collections, and to automatically update styles. An example of a filled-in section is shown below, and is followed by a description of all possible elements.<info><title>My first style</title><id>http://www.zotero.org/styles/my-style-name</id><linkhref="http://www.zotero.org/styles/my-style-name"/><author><name>My name</name><email>email@example.com</email><uri>http://wherever.com/</uri></author><categoryterm="author-date"/><categoryterm="zoology"/><updated>2008-10-29T21:01:24+00:00</updated><summary>My great new style format.</summary><rights>This work is licensed under a Creative Commons Attribution-Share Alike 3.0 Unported License http://creativecommons.org/licenses/by-sa/3.0/</rights></info>
Many elements available in the info section are borrowed from the Atom Syndication Format:
: this required field should preferably be a valid, stable, and unique URL if the style is to be made publicly available. Make sure you choose the id carefully, as it will be used to identify the style (if a style is installed in Zotero, it will overwrite an already present style with the same id). For styles uploaded to the Zotero Style Repository this can be the link to your schema (e.g. http://www.zotero.org/styles/your-style-filename).
: name of the style (required). The title is shown in the Zotero Style Repository.
- //(): people who write a new style, or make significant changes can claim authorship (see example above). For smaller changes the contributor role can be used. In both cases one should supply a name. An email-address and URI are optional.
: the contents of this required element is used to assess whether the style has changed since the last time it has been accessed or cached. If uploading to the Zotero Style Repository, the timestamp will be generated automatically. The syntax of the timestamp is described here.
: similar to updated, this element contains a timestamp, in this case the timepoint when the style was initially created or first made available.
: styles can be divided in a number of categories. This information can be used to ease browsing of large style repositories and could allow users to subscribe to styles within particular content areas. The different types of categories are:
the style's class, which describes how in-text citations are rendered:
: e.g. “… (Doe, 1999)”
: e.g. “… ”
: “ … [doe99].”
: the citation appears as a footnote or endnote
: the full citation appears in-line
the field(s) the style applies to (the category is meant for generic styles like Harvard and APA): , , , , , , , , , , , , , , , , , , , , , , , ,
: a license dictating how the style file may be modified and distributed by others. See, e.g. http://creativecommons.org/license/
: a style written for a specific journal can include the journal's ISSN (International Standard Serial Number). N.B. currently Zotero only supports a single ISSN. There are plans to add a element to allow for inclusion of the ISSN-L, and also to allow for multiple ISSNs (as many journals have both a print and online ISSN).
The construct is a key part of the style, and describes how in-line citations should be formatted. Sometimes a citation will only be a simple number, in other cases a more elaborate citation is desired, as is the case for author-date styles. The basic structure of the construct is as follows:<citation><option/><layout> some layout </layout></citation>
The specifies what information should be included in the citation. Additional control is possible with a range of options, which will be discussed later. Already for the element itself some optional parameters can be set, the most common being a prefix, suffix and delimiter. The delimiter functions in distinguishing multiple items in a single citation. For instance<layoutprefix="("suffix=")"delimiter="; ">
would result in a citation like “(item1;item2)”, where the contents of the element would describe how item1 and item2 should be formatted (e.g. as “(Doe 1999; Johnson 2002)”).
This is the second of the key parts, where the bibliography is formatted. It is very similar to the citations section.<bibliography><option .../><layout> ... </layout></bibliography>
Again, a set of options to control some of the layout, then the layout itself.
A list of macro definitions is usually included between the and sections. These are sort of like subroutines that can be called later in the description to make similar styles for parts. Effective use of macros is a key to making good styles. Ideally, in fact, the main layout sections for the citation and bibliography should be quite simple, and simply call a series of macros.
An example macro is<macroname="editor-translator"><namesvariable="editor translator"prefix="("suffix=")"delimiter=", "><nameand="symbol"initialize-with=". "delimiter=", "/><labelform="short"prefix=", "text-transform="capitalize"suffix="."/></names></macro>
It is particularly crucial in author-date styles that rely on author names for sorting that one create a macro that can handle a wide variety of cases, including resources that do no include listed authors. Example:<macroname="author"><namesvariable="author"><namename-as-sort-order="all"and="symbol"sort-separator=", "initialize-with=". "delimiter=", "delimiter-precedes-last="always"/><labelform="short"prefix=" ("suffix=".)"text-transform="capitalize"/><substitute><namesvariable="editor"/><namesvariable="translator"/><textmacro="title"/></substitute></names></macro>
This example includes the logic that allows the formatter to gracefully adapt to a wide-range of resource types. Likewise, one could create a macro for titles like so:<macroname="title"><choose><iftype="book"><textvariable="title"text-case="sentence"font-style="italic"/></if><else><textvariable="title"text-case="sentence"/></else></choose></macro>
Note here that CSL reserves three types as generic fallbacks. In this case, for example, “book” is a generic fallback for all resources that have the characteristic that they are essentially self-contained items. So, for example, a music album will use this rule in the absence of any rules specific to its type.
Because of the value of macros and the potential to reuse them in different styles and automated software tools, it is recommended that you try to adapt common macro names, such as:
access (for URLs and archival locations)
event (for conference, hearings, etc.)
citation-locator (for cited pages and such)
locators (volume and issue, for example)
container-prefix (for the “In” and such that often preceded container info)
edition (for edition or version info)
CSL provides a number of localized strings like “et al.”, “vol.”, and “edited by”. However, in some cases you might want to change these preset strings. Specifying terms via the element allows you to do just that. Usually this element is included just below the element. An example is shown below:<terms><localexml:lang="en"><termname="editor"form="verb-short">ed. by</term><termname="editor"form="short"><single>edtr</single><multiple>edtrs</multiple></term></locale></terms>
A complete list of localized terms, together with their translations, can be found in the Zotero SVN repository.
Most of following syntax applies to the , and sections.
Styles are partially configured by setting a number of options. Some of these options are available in both the and sections, while others are specific to one of the two sections. Below a description and example is given for each option.
These apply to both and sections.
et-al-min - the minimum length of contributor lists (e.g. of authors or editors) for et-al abbreviation to kick in.
et-al-use-first - if et-al abbreviation is used, the number of contributors to be included before the et-al part.
Citation only options
et-al-subsequent-min - the minimum authors for et-al in subsequent references.
et-al-subsequent-use-first - the minimum authors for et-al in subsequent references.
disambiguate-add-year-suffix a true/false to indicate how to disambiguate two references that are otherwise the same. This adds a suffix to the year, so you'll get 2007a, 2007b etc.
disambiguate-add-names - add additional names, disregarding the “et-al” setting, to disambiguate the citations.
disambiguate-add-givenname - add a given name to a citation to disambiguate authors with the same last name, so J. Doe, 2005 compared to M. Doe, 2005.
collapse - this allows citations to be collapsed into an abbreviated style. The value is one of the following:
citation-number - collapses numeric citations from [1, 2, 3] to [1-3]
year - collapses multiple references to the same author to just the years. So (Doe 2000, Doe 2001) collapses to (Doe 2000, 2001).
year-suffix - collapses like in the year option, but also collapses (Doe 2000a, Doe 2000b) to (Doe 2000a, b). This is ignored if the disambiguate-add-year-suffix is not in use.
Bibliography only options
hanging-indent - formats the bibliography with a hanging indent.
second-field-align - values of true or margin. It is most useful with numbered items and allows the number to be placed in the margin.
subsequent-author-substitute - substitutes subsequent recurrences of an author for a given string, such as “— — —”. Help wanted here!
Spacing in the Bibliography is controlled by the “entry-spacing” and “line-spacing” options
The sorting order for in-text citation groups [e.g. (Doe 2001; Johnson 2003)], and for the bibliography can be set with the element, in which one or multiple sort keys can be specified. Sort keys can consist of either variables or macros, e.g.:<citation><sort><keymacro="author"/><keyvariable="issued"sort="descending"/></sort></citation>
In this example, citations are first sorted by the output of the author macro. Multiple entries that share the same author macro output are further sorted in reverse order by date of issue (if not specified, the value of the attribute is assumed to be “ascending”). Using macros instead of variables as sort keys is especially useful in case of substitutions (e.g., if no authors are specified, sort according to the translators/editors), or when sorting should be according to year instead of date of issue.
These are the variables that can be used in the layout. They can also be tested in the syntax, and displayed with the syntax. They map to various things in the zotero entries. Some of them are available in both short and long form.
title - maps to the Title field in the long form, and the Short Title in the short form.
container-title - maps to Publication, Website Title, reporter, code
collection-title - maps to Series, Series Title
collection-number - maps to Series Number
original-title - no mapping.
publisher - maps to Publisher, Distributor, University
publisher-place - maps to Place.
event - maps to Meeting Name, Conference Name
event-place - maps to Place
page - maps to Pages
number-of-pages - maps to # of Pages.
references - maps to History (Bill)
locator - maps to the location in the cite dialog.
version - maps to Version
volume - maps to Volume.
number-of-volumes - maps to # of Volumes.
issue - maps to Issue.
medium - maps to Medium (Interview), Format (Film, Videorecording, Audiorecording)
status - no mapping
section - maps to Section (Bill)
edition - maps to Edition.
genre - maps to Type, Artwork Size.
note - maps to Extra
annote - no mapping.
authority - maps to Court (Case)
abstract - maps to Abstract.
keyword - no mapping.
number - maps to Bill Number, Docket Number
archive - maps to Repository.
archive_location - maps to Loc. in Archive.
archive-place - no mapping.
URL - maps to URL.
DOI - maps to DOI.
ISBN - maps to ISBN.
citation-number - maps to the number of the citation.
citation-label - no mapping.
These are the types of author that can be used in the layout. They can be displayed with the syntax. They map to various things in the zotero entries. Some of them are available in both short and long form.
author - maps to the Author field.
editor - maps to the Editor.
translator - maps to the Translator.
publisher - no mapping.
original-author - no mapping.
original-publisher - no mapping.
recipient - no mapping
interviewer - no mapping
collection-editor - maps to the Series Editor field.
composer - no mapping
Author markup is done using the and directives. The names wraps the whole thing, and the name how to format an individual. The names also allows a <substitute> block to fill in with other syntax. For the <name> block, there are a number of options that can be specified, besides the generic formatting:
form - long or short.
and - set to either symbol to use & or text to use the word “and” to combine authors.
delimiter - set to something like “,” to separate names.
delimiter-precedes-last - always uses the delimiter even for the last author, never doesn't.
name-as-sort-order - determines the order of last name and first name(initials). No entry has all authors as firstname-lastname, “first” displays only the first author as lastname-firstname, “all” displays all authors as lastname-firstname.
sort-separator - some text to separate the first and last names.
initialize-with - the text to follow each initial and a directive to use initials.
e.g.,<namesvariable="author"><nameform="short"and="symbol"delimiter=", "initialize-with=". "/></names>
The <substitute> comes into play if the named author variable is missing. It allows other things to be substituted. For instance<namesvariable="author"><namename-as-sort-order="all"and="symbol"sort-separator=", "initialize-with=". "delimiter=", "delimiter-precedes-last="always"/><labelform="short"prefix=" ("suffix=".)"text-transform="capitalize"/><substitute><namesvariable="editor"/><namesvariable="translator"/><textmacro="title"/></substitute></names>
would fill in with the editor, translator or the title in that order.
There are various date fields that can be used. These are typically displayed with the markup.
issued - maps to the Date.
event - no mapping
accessed - maps to Accessed.
container - no mapping.
Dates are processed with the and markup. The part is a wrapper around the block, and specifies the date you are working with. This usually encapsulates a sequence of directives. The date as a whole can have the usual formatting directives. The <date-part> lets you format individual parts of the date. The parameters, apart from the usual formatting constructs, are
month - which can also have the form attributes
short (e.g. Jan)
long (e.g. January)
numeric (e.g. 1)
numeric-leading-zeros (e.g. 01)
day - which can also have the form attributes
numeric (e.g. 1)
numeric-leading-zeros (e.g. 01)
ordinal (e.g. 1st)
year - which can be with form short or long. (e.g. 05 or 2005)
other - other bits of the date (time maybe) also in short/long form.
For example:<datevariable="issued"suffix=";"><date-partname="year"suffix=" "/><date-partname="month"form="short"suffix=" "/><date-partname="day"/></date>
Although a delimiter can be specified in the date part, it is used to separate multiple dates and not to separate parts of the date. Therefore prefix and suffix are important in the date-part.
The <text> directive is the way to include text in the output from a variety of sources. For example:<textvariable="title"prefix=" Title: "form="short"/>
The first parameter can be one of:
variable - include the contents of a variable.
macro - output the results of evaluating a macro.
term - output a specific term which is subject to localisation
value - output a given bit of verbatim text.
Other parameters you can include are
form - either short or long, only makes sense with certain variables (otherwise defaults to long).
include-period - true/false term that adds a '.' if parameter is of type “term” and the term used is an abbreviation, not a long form or symbol
You can also include any of the Formatting directives.
The following formatting parameters for most elements specifying output.
: text to insert before the main output
: text to insert after the main output
: which font family to use.
: , or (slanted).
: or .
: , or .
: or .
(modifies the capitalization of the text): , , , , , .
: , or .
: if set to makes this a block of separate text.
: true/false to include quotes around it.
For instance<textvariable="edition"prefix=" "suffix=" ed. "/><textterm="retrieved"text-transform="capitalize"suffix=" "/>
Labels are used to add common text that may be dependent on the item. An example is the label for pages, which can be p. or pp. depending on the number of pages referenced. For instance<groupprefix=" ("suffix=")"><labelvariable="page"form="short"suffix=". "/><textvariable="page"/></group>
is the other variable commonly used. Label elements allow for the usual text formatting, the choice between different forms (short, long, etc.) and an option to include a trailing '.'. Labels can also be applied without a variable inside a element. In this case, the label is the role label (e.g., “edited by”)
The group construct allows you to group together elements with a format applied to the whole group.<groupdelimiter=": "><textvariable="publisher-place"/><textvariable="publisher"/></group>
The group is ignored if it contains no variables that exist in the document, even if it contains locale terms. A group can also represent semantic document components, as in:<groupclass="container"prefix=". ">
Conditional information is tested with the construct, which must be embedded in a block. There is an and an to allow multi-way choices. It is common in bibliographies to do different arrangements based on the type, as in<choose><iftype="book"> ... </if><else-iftype="chapter"> ... </else-if><else> ... </else></choose>
Things that can be tested are type's as above, variables (which includes authors and dates). Also are a few meta variables which include
which can be tested against , , , . The first time a citation is made to a certain item, the position will be . If the next citation again references that item, the position becomes , or, if a locator is added in the Insert Citation window, . Finally, if the same item is again referenced after some other items have been cited, the position becomes .
which can be tested against true/false. This allows two citations to see if they are the same still.
which can be compared against locator types such as , , etc.
- this allows and/or/not like behaviour by setting against //. This is required if you test multiple types or variables too.
Multiple variables can be tested as in<iftype="chapter book"match="any">
Here is a list of Zotero item types which have a specific mapping (a complete table of item types and associated field mappings is available here). For example your CSL code must use “paper-conference” if you want to refer to the “Conference Paper” type. Note that some item types are not, at the moment, mapped (e.g.: encyclopediaArticle). These types can be tested in the syntax.
article-journal - maps to journalArticle Type
article-magazine - maps to magazineArticle
article-newspaper - maps to newspaperArticle
thesis - maps to thesis
paper-conference - maps to conferencePaper
personal_communication - maps to letter, email and instantMessage
manuscript - maps to manuscript
interview - maps to interview
motion_picture - maps to film
graphic - maps to artwork
webpage - maps to webpage
report - maps to report
bill - maps to bill, hearing (?) and statute (?)
legal_case - maps to case
patent - maps to patent
map - maps to map
book - maps to computerProgram (?)
webpage - maps to blogPost and forumPost
song - maps to audioRecording (?) and podcast (?)
speech - maps to presentation
motion_picture - maps to videoRecording
broadcast - maps to tvBroadcast and radioBroadcast
However CSL reserves some types as generic fallbacks. Thus, for example, a film will use the rule which has been defined for book in the absence of any rules specific to its type.
You must test a specific type before its generic fallback. For instance, as “book” is the fallback for “film”, you need to test for “film” before testing for “book” if you want it to work correctly.
“book” is a generic fallback for book, film, artwork, report, bill, case, hearing, statute, audioRecording, videoRecording and computerProgram.
“article” is a generic fallback for journalArticle, magazineArticle, newspaperArticle, thesis, letter, manuscript, interview, webpage, patent, email, map, blogPost, instantMessage, forumPost, tvBroadcast, radiobroadcast, podcast and presentation.
“chapter” is a generic fallback for bookSection, encyclopediaArticle, dictionaryEntry, conferencePaper.
Hi everyone, I have two related questions about customising citation styles.
For my document, I need a style whereby in-text citations are mentioned as footnotes, with only Name+Year as the details given in each footnote. It seems the "Chicago Manual of Style 16th edition (note)" style (which is Name+Title) comes closest, as it only needs customising to change Title into Year.
To that end, I followed Zotero documentation and tried to download this modified style from the Zotero Style Repository. However, there, the preview that it shows me is very different (much more details is shown, and NO footnotes) from how this style is (correctly) applied in my document. How can I modify the style as desired?
Also: can the FootnoteText style, that Zotero employs to list the references, be laid out on 2/3 columns? I see no such option in the style settings, and there seems anyway to be a bug (see my previous thread) with how Zotero actually follows style settings for listing references! If I change the footnote settings directly from Word's ribbon, Zotero makes a mess of the footnote section, so it probably has to be done through Zotero somehow.
Using Word 2016, Zotero 220.127.116.11, Firefox 55.0.3, Win 7. Many thanks!