Help:システムメッセージ

This page is a translated version of the page Help:System message and the translation is 26% complete.

注意: このページを編集すると、編集内容が CC0 のもとで公開されることに同意したと見なされます。詳細はパブリック・ドメインのヘルプページを参照してください。

国際化の説明文書

システムメッセージは平文やウィキテキスト、CSS、JavaScript のスニペットで、MediaWikiの振る舞いや、それぞれの言語とロケール (英語版) に合わせて外見をカスタマイズするために使用されます。 MediaWiki は利用者から見えるインターフェイスの要素すべてにメッセージを使っており、コアと拡張機能の両方で MediaWiki UI の国際化と地域化を可能にしています。 MediaWiki で使用されているメッセージはすべてメッセージファイル内で定義されています。

ウィキ上でのメッセージのオーバーライド

ウィキ上でメッセージを編集することでメッセージの既定値を上書きできます。各メッセージには、MediaWiki 名前空間内に対応するウィキページがあり、そのページ名はメッセージキーになっています。例えば、「aboutsite」メッセージはMediaWiki:aboutsiteに格納されています。既定では、「editinterface」権限を持っていない利用者は、この名前空間のページを編集できません。すべてのメッセージページの一覧は、Special:AllMessages にあります。インターフェイスメッセージの編集は簡単で、通常のウィキページの編集と同様ですが、editinterface 権限を持つ利用者のみに編集が制限されています。この権限は既定では、管理者 (およびインターフェース管理者) に割り当てられています。

古い Special:AllMessages の行の例。

Special:AllMessages の表には 2 つの列があります: リンクされたインターフェイス名とメッセージ文です。メッセージ文は上下に 2 分割されていて、上に既定のメッセージ文、下にカスタマイズされたメッセージ文を表示します。カスタムメッセージ文が存在しない場合、既定のメッセージ文のみが表示されます。メッセージをカスタマイズするには、左の列の上にあるリンクをクリックします (メッセージ名)。既定のメッセージ文が使用されている場合、編集ページが空であるためこのリンクは赤く表示されます。

左カラムのセルにある下側のリンクはそのメッセージのための議論ページになります。

Overriding messages on the wiki is recommended only in the following cases:

The message has a severe mistake that must be fixed as soon as possible. In this case, it's recommended to also fix this mistake in the source code if it's in English or in the translation on translatewiki if it's not. When the correction is deployed, the page with the local customization should be deleted.
If the local wiki uses different terminology. For example, many messages use the word "page", but the English Wikipedia often says "article" instead.
The local message is trying to add some unique functionality, for example for a gadget or a template. (In such a case, it is still recommended to consider changing the source message or to encapsulate this functionality in an extension, so that other wikis would be able to enjoy it conveniently, without having to copy customizations manually.)

メッセージとその説明文を見つける

各メッセージが MediaWiki でどのように使用されているか、利用できる変数、使用されているパラメーター、制限などについては、仮想言語 qqq 内の完全な説明文書ファイルで、メッセージ説明文書のガイドラインに従って説明されています。一部のインターフェイスメッセージの長い説明ページについては、より古いカテゴリ:インターフェイスメッセージ内にある場合があります。

translatewiki.net のウィキベースでは、qqq はメッセージの利用者向け説明文書を保持するページです (すべての読者に同じように表示するため英語で記述)。

/en, /zu, /fr, ..., /qqq が記事の下位ページであり直接閲覧できるのと同様です。

メッセージを英語で閲覧するには translatewiki:MediaWiki:Tog-hideminor/en をお試しください。
メッセージをフランス語で閲覧するには translatewiki:MediaWiki:Tog-hideminor/fr をお試しください。
関連付けられた説明文書を表示するには translatewiki:MediaWiki:Tog-hideminor/qqq をお試しください (英語)。

この観点から、qqq は、リクエストのパラメーター language= では言語とみなされます。

MediaWiki バージョン:

≧ 1.18

MediaWiki 1.18 以降では、擬似言語コード qqx を使ってウィキ内のメッセージ・キーを検索できます。通常は URL の文字列の後に ?uselang=qqx を、もしくは ? 文字を含む URL であれば&uselang=qqx を足します（例）。するとすべてのメッセージはメッセージキーに置換され、どのメッセージが該当するか識別しやすくなります。常にコンテンツの表示言語で表示させるメッセージは qqx を使わずに表示されます。

特別ページ「個人設定」のようにタブに分かれたページの場合、uselang パラメーター（例：Special:Preferences?uselang=qqx#mw-prefsection-rendering）の後にタブを追加する必要があります。

MediaWiki バージョン:

≧ 1.38

Gerrit change 765385

Before MediaWiki 1.38, fallback message keys were not shown, which made it difficult to identify the source of some messages, notably the page navigation tabs. Since MediaWiki 1.38 fallback message keys are shown separated by slashes (/).

MediaWiki バージョン:

≧ 1.43

Gerrit change 1025837

Before MediaWiki 1.43, override message keys (using hooks like MessageCacheFetchOverrides) were not shown either, which made it difficult to identify the source of messages overridden by extensions (such as WikimediaMessages ). Since MediaWiki 1.43 override message key is shown after an equals sign (=).

地域化ファイルの書式

MediaWiki で使用されているメッセージはすべて「メッセージファイル」内で定義されています。

MediaWiki のメッセージファイルには、JSON と PHP の 2 種類があります。 2014年4月時点で、コア MediaWiki と保守されている拡張機能のほとんどが JSON 形式に移行されました。新規の開発ではすべて JSON を使用すべきです。 JSON への移行の詳細は、Requests for comment/Localisation format を参照してください。

JSON

2013年後半から、メッセージの新しいファイル形式「JSON」が導入されました。これは、一般的な汎用データ保存形式として親しまれている、プレーンな JSON です。その中のすべてのキーがメッセージキーであり、値がメッセージテキストです。また、特殊な @metadata キーは、翻訳の作者などの翻訳についての情報を保存するために使用されます。

JSON を使用すると、地域化ファイルが実行できなくなるため、より安全性が高くなります。また、プロジェクト Milkshake の一部として開発された JavaScript ライブラリである jquery.i18n と互換性があり、MediaWiki のようなフロントエンドの地域化機能を提供し、ビジュアルエディターやユニバーサル言語選択など、MediaWiki にあまり依存したくないいくつかの拡張機能が使用します。

国際化・地域化ツール一式が「Project Milkshake」と呼ばれていたことから、この形式を「バナナ」と呼ぶ人もいます。

ファイルの場所

In MediaWiki core, localisation files are placed in the languages/i18n directory. MediaWiki extensions usually place theirs in an i18n/ subdirectory. If a large number of messages exist within a project, one may want to split these into two or more topical subdirectories for maintainability. In MediaWiki context, the $wgMessagesDirs configuration key is used to list these subdirectories. Here's an example from the VisualEditor extension for MediaWiki:

{
  "MessagesDirs": {
    "VisualEditor": [
      "lib/ve/modules/ve/i18n",
      "modules/ve-mw/i18n",
      "modules/ve-wmf/i18n",
      "lib/ve/lib/oojs-ui/i18n"
    ]
  }
}

You add new messages to the English "en" messages file en.json and document them in the message documentation file with the special pseudo-language code "qqq" – qqq.json. See also: Adding new messages.

メタデータ

Currently the following metadata fields are used in the files:

authors: A JSON list of the authors of the messages. For English (en) and message documentation (qqq) these are added manually when the messages file is edited. For all other languages this is inserted automatically when the message file is exported from translatewiki.net. Message documentation can be edited on translatewiki.net, and documentation editors are inserted to the qqq.json file automatically as well.
message-documentation: This is the pseudo-language code for storing the message documentation. For MediaWiki this is always qqq. (This appears in some extensions, but it's not actually processed in any way. It's not mandatory.)

規約

Special characters like line breaks are escaped ("\n").

Unicode characters that represent letters in different alphabets are stored as real characters and not as character codes, because these files are sometimes read by people and because this makes the files smaller ("誼" and not "\u8ABC"). In any case, developers have few reasons to edit messages in any languages except English, because these are usually edited through translatewiki.net.

HTML code is not escaped either, so "Warning" and not "\u003cstrong\u003eWarning\u003c/strong\u003e".

The JSON files are indented using tabs.

PHP

This section refers to the use of MessagesXx.php files for localizing messages, which has been deprecated in 2014. However, the files are still used for other language-specific configuration.

The older localisation file format is PHP. This is essentially a PHP array with all the messages. In core MediaWiki each language resides in its own file in the languages/message directory of the MediaWiki source code. In the extensions all the languages and the message documentation (qqq) are in the same file: ExtensionName.i18n.php, usually in the main directory of the extension.

To migrate system messages from PHP to JSON, use the generateJsonI18n.php script. It will move the messages to JSON files and replace the text of the PHP file with a shim that points to the JSON files. This boilerplate code is needed for backwards compatibility with MediaWiki 1.19. It is not used in new extensions that do not require MediaWiki 1.19 compatibility.

メッセージの使用

MediaWiki では、コード内のキーによって参照されるメッセージの、中央管理 リポジトリ方式を使用しています。この方式は、例えば gettext などが採用している、ソースファイルから翻訳可能文字列を抽出するだけの方式とは異なります。キーベースのシステムでは、翻訳元のテキストの改善や、メッセージの変更の追跡がより容易になります。もちろん使用されたメッセージの一覧やそれらのキーに対応する翻訳原文の一覧が陳腐化するという欠点はつきものです。実用上は大きな問題ではなく、特筆するべき唯一の問題点とはどこにも使われなくなった余計なメッセージでも翻訳対象として残る点です。

メッセージキーの管理と検索の利便性を高めるには、grep も含め、常に記述を完結させなおかつ動的な定義を避けることです。 You may concatenate parts of message keys if you feel that it gives your code better structure — but only do this when there definitely are multiple possibilities,^[1] and be sure to put a comment nearby with a list of the possible resulting keys. 例：

// ここで使用できるメッセージ例:
// * myextension-connection-success
// * myextension-connection-warning
// * myextension-connection-error
$text = wfMessage( 'myextension-connection-' . $status )->parse();

動的識別子のコーディング規約も参照してください。

JavaScript で用いるメッセージは、ご利用のResourceLoader モジュールの定義内に一覧として加えることで、属性は "messages" になります。

PHP および JavaScript 内でのメッセージ関数の使用方法の詳細は、Manual:メッセージAPI を参照してください。 この解説ページは重要で、メッセージを用いるコードを書く前に必ず通読しなければなりません。

メッセージのソース

Code looks up system messages from these sources:

MediaWiki 名前空間。 This allows wikis to adopt, or override, all of their messages, when standard messages do not fit or are not desired.
- MediaWiki:Message-key is the default message,
- MediaWiki:Message-key/language-code is the message to be used when a user has selected a language other than the wiki's default language.
From message files:
- Core MediaWiki itself and most currently maintained extensions use a file per language, named zyx.json, where zyx is the language code for the language.
- Some older extensions use a combined message file holding all messages in all languages, usually named MyExtensionName.i18n.php.
- Many Wikimedia Foundation wikis access some messages from the WikimediaMessages extension, allowing them to standardise messages across WMF wikis without imposing them on every MediaWiki installation.
- A few extensions use other techniques.

キャッシュ

System messages are one of the more significant components of MediaWiki, primarily because it is used in every web request. The PHP message files are large, since they store thousands of message keys and values. Loading this file (and possibly multiple files, if the user's language is different from the content language) has a large memory and performance cost. An aggressive, layered caching system is used to reduce this performance impact.

MediaWiki はいくぶんかコードの理解を難しくする組み込みのキャッシングメカニズムをたくさん持っています。 Since 1.16 there is a new caching system, which caches messages either in cdb files or in the database. Customised messages are cached in the filesystem and in memcached (or alternative), depending on the configuration.

The table below gives an overview of the settings involved:

キャッシュ格納領域の場所		$wgLocalisationCacheConf
キャッシュ格納領域の場所		'store' => 'db'	'store' => 'detect' (既定)	'store' => 'files'	'store' => 'array' (experimental since MW ≥ 1.26)
$wgCacheDirectory	= false (既定)	l10n cache table	l10n cache table	エラー (パスが未定義)	エラー (パスが未定義)
$wgCacheDirectory	= path	l10n cache table	ローカルファイルシステム (CDB)	ローカルファイルシステム (CDB)	ローカルファイルシステム (PHP 配列)

MediaWiki バージョン:

1.27.0 – 1.27.2

Gerrit #Id3e2d2

In MediaWiki 1.27.0 and 1.27.1, the autodetection was changed to favor the file backend. In case 'store' => 'detect' (the default), the file backend is used with the path from $wgCacheDirectory . If this value is not set (which is the default), a temporary directory determined by the operating system is used. If a temporary directory cannot be detected, the database backend is used as a fallback. This was reverted from 1.27.2 and 1.28.0 because of conflict of files on shared hosts and security issues (see T127127 and T161453).

Function backtrace

To better visually depict the layers of caching, here is a function backtrace of what methods are called when retrieving a message. See the below sections for an explanation of each layer.

Message::fetchMessage()
MessageCache::get()
Language::getMessage()
LocalisationCache::getSubitem()
LCStore::get()

MessageCache

The MessageCache class is the top level of caching for messages. It is called from the Message class and returns the final raw contents of a message. This layer handles the following logic:

Checking for message overrides in the database
Caching over-ridden messages in memcached , or whatever $wgMessageCacheType is set to
Resolving the remainder of the language fallback sequence

The last bullet is important. Language fallbacks allow MediaWiki to fall back on another language if the original does not have a message being asked for. As mentioned in the next section, most of the language fallback resolution occurs at a lower level. However, only the MessageCache layer checks the database for overridden messages. Thus integrating overridden messages from the database into the fallback chain is done here. If not using the database, this entire layer can be disabled.

LocalisationCache

LocalisationCache.php を参照

LCStore

The LCStore class is merely a back-end implementation used by the LocalisationCache class for actually caching and retrieving messages. Like the BagOStuff class, which is used for general caching in MediaWiki, there are a number of different cache types (configured using $wgLocalisationCacheConf ):

"db" (default) - Caches messages in the database
"file" (default if $wgCacheDirectory is set) - Uses CDB to cache messages in a local file
"accel" - Uses APC or another opcode cache to store the data

The "file" option is used by the Wikimedia Foundation, and is recommended because it is faster than going to the database and more reliable than the APC cache, especially since APC is incompatible with PHP versions 5.5 or later.

新しいメッセージの追加

メッセージキーを選ぶ

関連項目: Manual:コーディング規約

The message key must be globally unique. This includes core MediaWiki and all the extensions and skins.

メッセージの名前はアルファベットの小文字、数字、ダッシュのみで記述します。その他の文字は実用性が低いかまったく役に立たないかのどちらかです。 Per MediaWiki convention, first character is case-insensitive and other chars are case-sensitive.

Please follow global or local conventions for naming. For extensions, use a standard prefix, preferably the extension name in lower case, followed by a hyphen (-). 例外は以下の通りです:

APIによって使用されるメッセージ: These must begin with apihelp-, apiwarn-, apierror-. After this prefix put the extension prefix. (Note that these messages should be in a separate file, usually under includes/i18/api.)
Log-related messages: These must begin with logentry-, log-name-, log-description.
利用者権限: The key for the name of the right as displayed on Special:ListGroupRights must begin with right-. The name of the action that completes the sentence "あなたには「$2」を行う権限がありません。理由は以下の通りです:" must begin with action-.
Revisions tags: Revisions tags must begin with tag-.
Special page titles: Special page titles must begin with special-.
Extension descriptions: Extension descriptions must begin with the extension name and end with -desc.

They appear in the table on Special:Version, and their content must briefly explain what the extension does.

ジェンダー

English messages almost never need different words that change because of a user's gender. English only needs this in the third-person pronouns "he" and "she", but these are surprisingly rare in messages. When this is necessary, use he or they.

However, many other languages need different words depending on the user's gender, not only for third-person pronouns, but also for other pronouns, as well as for verbs in different tenses (e.g. "created", "deleted"), nouns (e.g. "mentor", "administrator"), adjectives (e.g. "new"), etc. It is therefore often useful to use GENDER in English messages, even when there's only English word. This gives translators a hint that GENDER can be used in a message. It also avoids warnings on translatewiki about missing parameters when an optional username parameter is missing (this happens especially often in log entry messages).

メッセージを作成するときにその他に注意すること

Make sure that you are using suitable handling for the message (parsing, {{-replacement, escaping for HTML, etc.)
If your message is part of core, it should usually be added to languages/i18n/en.json, although some components, such as Installer, EXIF tags, and ApiHelp have their own message files.
If your message is in an extension add it to the i18n/en.json file or the en.json file in the appropriate subdirectory. In particular, API messages that are only seen by developers and not by most end users are usually in a separate file, such as i18n/api/en.json. If an extension has a lot of messages, you may create subdirectories under i18n. All the message directories, including the default i18n/, must be listed in the MessagesDirs section in extension.json or in the $wgMessagesDirs variable.
Take a pause and consider the wording of the message. Is it as clear as possible? Can it be misunderstood? Ask for comments from other developers or localisers if possible. Follow the Internationalisation hints.
Add documentation to qqq.json in the same directory.
The sequence of the messages in the file should roughly conform to the features of your project. Put messages from the same feature next to each other. This helps translators stay focused and be efficient and consistent.
Put the messages that are expected to be the most basic and the most frequently used in the beginning of the file, and the messages that are rarer and more technically advanced towards the end.

翻訳するべきではないメッセージ

Ignored messages are those which should exist only in the English messages file. They are messages that should not need translation, because they reference only other messages or language-neutral features, e.g. a message of "{{SITENAME}}".
Optional messages may be translated only if changed in the target language.

To flag such messages:

use the template in the qqq message documentation, that is respectively
1. {{notranslate}} または
2. {{optional}};
tell the Translate extension used on translatewiki.net what to do with the messages by submitting a patch listing them as appropriate (see also full configuration docs ):
- for core, in groups/MediaWiki/MediaWiki.yaml add the message keys
  1. under ignored: or
  2. under optional:;
- for extensions, in groups/MediaWiki/mediawiki-extensions.txt add a line under the extension's name like
  1. ignored = msg-key-1,msg-key-2 or
  2. optional = msg-key-1,msg-key-2.

既存のメッセージの除去

Remove it from en.json and qqq.json. 他の言語版はそのままにしておきます。 Updates from translatewiki.net will handle those automatically.

In addition, check whether the message appears anywhere in translatewiki configuration, for example in the list of optional or most used messages (a simple git grep should be enough). Remove it from these lists if needed.

既存のメッセージの変更

Consider updating the message documentation.
Change the message key if old translations are not suitable for the new meaning. This also includes changes in message handling (parsing, escaping, parameters, etc.). Improving the phrasing of a message without technical changes is usually not a reason for changing a key. At translatewiki.net, the translations will be marked as outdated so that they can be targeted by translators. Changing a message key does not require talking to the i18n team or filing a support request. However, if you have special circumstances or questions, ask in #translatewiki ^接続 or in the support page at translatewiki.net .
If the extension is supported by translatewiki.net , please only change the English source message and/or key, and the accompanying entry in qqq.json. If needed, the translatewiki.net team will take care of updating the translations, marking them as outdated, cleaning up the file or renaming keys where possible. This also applies when you're only changing things like HTML tags which you could change in other languages without speaking those languages. Most of these actions will take place in translatewiki.net and will reach Git with about one day of delay.

メッセージについての説明文

There is a pseudo-language code qqq for message documentation. It is one of the ISO 639 codes reserved for private use. There, we do not keep translations of each message, but collect English sentences about each message: telling us where it is used, giving hints about how to translate it, and enumerating and describing its parameters, link to related messages, and so on. In translatewiki.net, these hints are shown to translators when they edit messages.

Programmers must document each and every message. Message documentation is an essential resource – not just for translators, but for all the maintainers of the module. Whenever a message is added to the software, a corresponding qqq entry must be added as well; revisions which don't do so are marked "V-1" until the documentation is added.

Documentation in qqq files should be edited directly only when adding new messages or when changing an existing English message in a way that requires a documentation change, for example adding or removing parameters. In other cases, documentation should usually be edited in translatewiki. Each documentation string is accessible at https://translatewiki.net/wiki/MediaWiki:message-key/qqq, as if it were a translation. These edits will be exported to the source repositories along with the translations.

Useful information that should be in the documentation includes:

Message handling (parsing, escaping, plain text).
Type of parameters with example values.
Where the message is used (pages, locations in the user interface).
How the message is used where it is used (a page title, button text, etc.).
What other messages are used together with this message, or which other messages this message refers to.
Anything else that could be understood when the message is seen on the context, but not when the message is displayed alone (which is the case when it is being translated).
If applicable, notes about grammar. For example, "open" in English can be both a verb and an adjective. In many other languages the words are different and it's impossible to guess how to translate them without documentation.
Adjectives that describe things, such as "disabled", "open" or "blocked", must always say what are they describing. In many languages adjectives must have the gender of the noun that they describe. It may also happen that different kinds of things need different adjectives.
If the message has special properties, for example, if it is a page name, or if it should not be a direct translation, but adapted to the culture or the project.
Whether the message appears near other message, for example in a list or a menu. The wording or the grammatical features of the words should probably be similar to the messages nearby. Also, items in a list may have to be properly related to the heading of the list.
Parts of the message that must not be translated, such as generic namespace names, URLs or tags.
Explanations of potentially unclear words, for example abbreviations, like "CTA", or specific jargon, like "template", "suppress" or "stub". (Note that it's best to avoid such words in the first place!)
Screenshots are very helpful. Don't crop – an image of the full screen in which the message appears gives complete context and can be reused in several messages.

A few other hints:

Remember that very, very often translators translate the messages without actually using the software.
Most usually, translators do not have any context information, neither of your module, nor of other messages in it.
A rephrased message alone is useless in most circumstances.
Don't use designers' jargon like "hamburger", "nav", or "comps".
Consider writing a glossary of the technical terms that are used in your module. If you do it, link to it from the messages' documentation.

You can link to other messages by using {{msg-mw|message key}}. Please do this if parts of the messages come from other messages (if this cannot be avoided), or if some messages are shown together or in same context.

translatewiki.net provides some default templates for documentation:

{{doc-action|[...]}} - for action- messages
{{doc-right|[...]}} - for right- messages
{{doc-group|[...]|[...]}} - for messages around user groups (group, member, page, js and css)
{{doc-accesskey|[...]}} - for accesskey- messages

Have a look at the template pages for more information.

国際化のヒント

Besides documentation, translators ask developers to consider some hints so as to make their work easier and more efficient and to allow an actual and good localisation for all languages. Even if only adding or editing messages in English, one should be aware of the needs of all languages. Each message is translated into more than 300 languages and this should be done in the best possible way. Correct implementation of these hints will very often help you write better messages in English, too.

Localisation#Help_and_contact_info lists the main places where you can find the assistance of experienced and knowledgeable people regarding i18n.

メッセージのパラメーターやスイッチを適切に使用する

That's a prerequisite of a correct wording for your messages.

メッセージの再利用を避ける

The translators discourage message re-use. This may seem counter-intuitive, because copying and duplicating code is usually a bad practice, but in system messages it is often needed. Although two concepts can be expressed with the same word in English, this doesn't necessarily mean they can be expressed with the same word in every language. "OK" is a good example: in English this is used for a generic button label, but in some languages they prefer to use a button label related to the operation which will be performed by the button. Another example is practically any adjective: a word like "multiple" changes according to gender in many languages, so you cannot reuse it to describe several different things, and you must create several separate messages.

If you are adding multiple identical messages, please add message documentation to describe the differences in their contexts. Don't worry about the extra work for translators. Translation memory helps a lot in these while keeping the flexibility to have different translations if needed.

「継ぎ接ぎ」メッセージの回避

Languages have varying word orders, and complex grammatical and syntactic rules. Messages formed by multiple pieces of text, possibly with some indirection, also called "string concatenation", in code that cannot be directly controlled by translators, are called "lego" or "patchwork" messages in developers' jargon. It's practically impossible to translate "lego" messages correctly.

Make every message a complete phrase. Several sentences can usually be combined much more easily into a text block, if needed. When you want to combine several strings in one message, pass them in as parameters, as translators can order them correctly for their language when translating.

互いに引用するメッセージ

An exception from the rule may be messages referring to one another: 'Enter the original author's name in the field labelled "{{int:name}}" and click "{{int:proceed}}" when done'. This makes the message consistent when a software developer or wiki operator alters the messages "name" or "proceed" later. Without the int-trick, developers and operators would have to be aware of all related messages needing adjustment, when they alter one.

Write messages in natural language

As much as possible, write messages in natural, human language. Try reading the message aloud and think: is this something that sounds like correct, grammatical English that humans speak? If it's complex, hard to pronounce, or in any way unnatural in English, it will be even harder for translators and for users in other languages.

Avoid punctuation that is too technical or bureaucratic or that can't be read aloud. Slash (/) should usually be replaced with or. And/or should be replaced with and or or. Sentences with comma splice should be split into shorter sentences.

特定のプロジェクトに特化した用語やテンプレートを使用しない

MediaWiki is used by very diverse people, within the Wikimedia movement and outside of it. Even though it was originally built for an encyclopedia, it is now used for various kinds of content. Therefore, use general terms. For example, avoid terms like "article", and use "page" instead, unless you are absolutely sure that the feature you are developing will only be used on a site where pages are called "articles". Don't use "village pump", which is the name of an English Wikipedia community page, and use a generic term, such as "community discussion page", instead.

Don't assume that a certain template exists on all wikis. Templates are local to wikis. This applies to both the source messages and to their translations. If messages use templates, they will only work if a template is created on each wiki where the feature is deployed. It's best to avoid using templates in messages completely. If you really have to use them, you must document this clearly in the message documentation and in the extension installation instructions.

文章で時刻を日付から分離する

Some languages have to insert something between a date and a time which grammatically depends on other words in a sentence. Thus, they will not be able to use date/time combined. Others may find the combination convenient, thus it is usually the best choice to supply three parameter values (date/time, date, time) in such cases, and in each translation leave either the first one or last two unused as needed.

メッセージで `{{SITENAME}}` を避ける

{{SITENAME}} has several disadvantages. It can be anything (acronym, word, short phrase, etc.) and, depending on language, may need the use of {{GRAMMAR}} on each occurrence. No matter what, each message having {{SITENAME}} will need review in most wiki languages for each new wiki on which your code is installed. In the majority of cases, when there is not a general GRAMMAR configuration for a language, wiki operators will have to add or amend PHP code so as to get {{GRAMMAR}} for {{SITENAME}} working. This requires both more skills, and more understanding, than otherwise. It is more convenient to have generic references like "this wiki". This does not keep installations from locally altering these messages to use {{SITENAME}}, but at least they don't have to, and they can postpone message adaption until the wiki is already running and used.

Avoid references to visual layout and positions

What is rendered where depends on skins. Most often screen layouts of languages written from left-to-right are mirrored compared to those used for languages written from right-to-left, but not always, and for some languages and wikis, not entirely. Handheld devices, narrow windows, and so on may show blocks underneath each other, that would appear side-by-side on larger displays. Since site- and user-written JavaScript scripts and gadgets can, and do, hide parts, or move things around in unpredictable ways, there is no reliable way of knowing the actual layout.

It is wrong to tie layout information to content languages, since the user interface language may not be the page's content language, and layout may be a mixture of the two depending on circumstances. Non-visual user agents like acoustic screen readers and other auxiliary devices do not even have a concept of visual layout. Thus, you should not refer to visual layout positions in the majority of cases, though semantic layout terms may still be used ("previous steps in the form", etc.).

MediaWiki does not support showing different messages or message fragments based on the current directionality of the interface (see T30997).

The upcoming browser and MediaWiki support for East and North Asian top-down writing^[2] will make screen layouts even more unpredictable, with at least eight possible layouts (left/right starting position, top/bottom starting position, and which happens first).

画面の色の参照の回避

The colour in which something is rendered depends on many factors, including skins, site- and user-written JavaScript scripts and gadgets, and local user agent over-rides for reasons of accessibility or technological limitations. Non-visual user agents like acoustic screen readers and other auxiliary devices do not even have a concept of colour. Thus, you should not refer to screen colours. (You should also not rely on colour alone as a mechanism for informing the user of state, for the same reason.)

メッセージ内の翻訳されないHTMLマークアップの回避

HTML markup not requiring translation, such as enclosing ‎<div> tags, rulers above or below, and similar, should usually not be part of messages. They pose security risks, unnecessarily burden translators, increase message file size, and can accidentally being altered or skipped in the translation process. In general, avoid raw HTML in messages if you can.

翻訳済みのメッセージは想定外の長さに達することが多い!

Skimming foreign language message files, you almost never find translated messages shorter than Chinese ones and rarely shorter than English ones. However, you will often find translations that are much longer than English ones.

Especially in forms, in front of input fields, English messages tend to be terse, and short. That is often not kept in translations. Languages may lack the technical vocabulary present in English, and may require multiple words or even complete sentences to explain some concepts. For example, the brief English message "TSV file:" may have to be translated in a language as literally:

Please type a name here which denotes a collection of computer data that is comprised of a sequentially organised series of typewritten lines which themselves are organised as a series of informational fields each, where said fields of information are fenced, and the fences between them are single signs of the kind that slips a typewriter carriage forward to the next predefined position each. Here we go: _____ (thank you)

This is, admittedly, an extreme example, but you get the trait. Imagine this sentence in a column in a form where each word occupies a line of its own, and the input field is vertically centered in the next column. :-(

異なるものや概念を示すために非常に近い、類似または同一の単語を使用するのを避ける

For example, pages may have older revisions (of a specific date, time, and edit), comprising past versions of said page. The words revision, and version can be used interchangeably. A problem arises, when versioned pages are revised, and the revision, i.e. the process of revising them, is being mentioned, too. This may not pose a serious problem when the two synonyms of "revision" have different translations. Do not rely on that, however. It is better to avoid the use of "revision" aka "version" altogether, then, so as to avoid it being misinterpreted.

Basic words may have unforeseen connotations, or not exist at all

There are some words that are hard to translate because of their very specific use in MediaWiki. Some may not be translated at all. For example, there is no word "user" relating to "someone who uses something" in several languages. Similarly, in Kölsch the English words "namespace" and "apartment" translate the same word. Also, in Kölsch, they say "corroborator and participant" in one word since any reference to "use" would too strongly imply "abuse". The term "wiki farm" is translated as "stable full of wikis", since a single-crop farm would be a contradiction in terms in the language, and not understood, etc..

必要なときに `‎<code>`、`‎<var>`、および `‎<kbd>` タグを使用する

When talking about technical parameters, values, or keyboard inputs, mark them appropriately as such using the HTML tags ‎<code>, ‎<var>, or ‎<kbd>. Thus they are typographically set off form the normal text. That clarifies their sense to readers, avoiding confusion, errors and mis-representations. Ensure that your message handler allows such markup.

記号、コロン、括弧などはメッセージの一部

Many symbols are localisable, too. Some scripts have other kinds of brackets than the Latin script has. A colon may not be appropriate after a label or input prompt in some languages. Having those symbols included in messages helps to make better and less Anglo-centric translations, and also reduces code clutter.

For example, there are different quotation mark conventions used in «Norwegian», ”Swedish”, »Danish«, „German”, and 「Japanese」.^[3]

If you need to wrap some text in localized parentheses, brackets, or quotation marks, you can use the parentheses ($1) or brackets [$1] or quotation-marks "$1" messages like so:

wfMessage( 'parentheses' )->rawParams( /* text to go inside parentheses */ )->escaped()
wfMessage( 'brackets' )->rawParams( /* text to go inside brackets */ )->escaped()
wfMessage( 'quotation-marks' )->rawParams( /* text to go inside quotation marks */ )->escaped()

Do not expect symbols and punctuation to survive translation

Languages written from right to left (as opposed to English) usually swap arrow symbols being presented with "next" and "previous" links, and their placement relative to a message text may, or may not, be inverted as well. Ellipsis may be translated to "etc.", or to words. Question marks, exclamation marks, colons will be placed other than at the end of a sentence, not at all, or twice. As a consequence, always include all of those in the text of your messages, and never try to insert them programmatically.

終止符(句点)の使用

Do terminate normal sentences with full stops. This is often the only indicator for a translator to know that they are not headlines or list items, which may need to be translated differently.

アンカーにリンクする

リンクのウィキテキスト

Link anchors can be put into messages in several technical ways:

via wikitext:

… [[ウィキページ名|アンカー]] …,

via wikitext:

… [何らかのURL アンカー] …

the anchor text is a message in the MediaWiki namespace. Avoid it!

The latter is often hard or impossible to handle for translators, avoid fragmented or 'patchwork' messages here, too. Make sure that "some-url" does not contain spaces.

意味のあるリンクアンカーを使用する

Take care with your wording. Link anchors play an important role in search engine assessment of pages – both the words linked, and the target anchor. Make sure that the anchor describes the target page well. Always avoid commonplace and generic words. For example, "Click here" is an absolute no-go,^[4] since target pages are almost never about "click here". Do not put that in sentences around links either, because "here" was not the place to click. Instead, Use precise action words telling what a user will get to when following the link, such as "You can upload a file if you wish."

専門用語やスラングを避ける

Avoid developer and power user jargon in messages. Try to use a simple language whenever possible. Avoid saying "success", "successfully", "fail", "error occurred while", etc., when you want to notify the user that something happened or didn't happen. This comes from developers' perspective of seeing everything as true or false, but users usually just want to know what actually happened or didn't, and what they should do about it (if at all). So:

"The file was successfully renamed" -> "The file was renamed"
"File renaming failed" -> "There is a file with this name already. Please choose a different name."

空白や改行に気を付ける

MediaWiki's localised messages usually get edited within the wiki, either by wiki operations on live wikis, or by the translators on translatewiki.net. You should be aware of how whitespace, especially at the beginning or end of your message, will affect editors:

Spaces and line breaks (newlines) at the end of the message are always automatically removed by the wikitext editor. Your message must not end with a space or line break, as it will be lost when it's edited on the wiki.
Spaces and line breaks at the beginning are not automatically removed, but they are likely to be removed by accident during editing, and should be avoided.

Start and end your message with active text; if you need a newline or paragraph break around it, your surrounding code should deal with adding it to the returned text.

There are some messages which require a space at the end, such as 'word-separator' (which consists of just a space character in most languages). To support such use cases, the following HTML entities are allowed in messages and transformed to the actual characters, even if the message otherwise doesn't allow wikitext or HTML formatting:^[5]

  – space
  or   – non-breaking space
 – soft hyphen

On a related note, any other syntax elements affected by pre-save transforms also must not be used in messages, as they will be transformed when the message is edited on the wiki.

標準的な大文字化の使用

Capitalisation gives hints to translators as to what they are translating, such as single words, list or menu items, phrases, or full sentences. Correct (standard) capitalisation may also play a role in search engines' assessment of your pages. MediaWiki uses sentence case (The quick brown fox jumps over the lazy dog) in interface messages.

Always remember that many writing systems don't have capital letters at all, and some of those that do have them, use them differently from English. Therefore, don't use ALL-CAPS for emphasis. Use CSS, or HTML ‎ or ‎ per below:

強調

In normal text, emphasis like boldface or italics and similar should be part of message texts. Local conventions on emphasis often vary, especially some Asian scripts have their own. Translators must be able to adjust emphasis to their target languages and areas. Try to use "‎" and "‎" in your user interface to allow mark-up on a per language or per script basis.

In modern screen layouts of English and European styles, emphasis becomes less used. Do convey it in your #Message documentation still, as it may give valuable hints as to how to translate. Emphasis can and should be used in other cultural contexts as appropriate, provided that translators know about it.

注記

↑ Some linters will reject message lists with just one item, e.g.: mediawiki/msg-doc doesn't accept valid docs with 1 entry.
↑ http://dev.w3.org/csswg/css3-writing-modes/
↑ w:Quotation_mark#Summary_table
↑ http://www.w3.org/QA/Tips/noClickHere
↑ https://github.com/wikimedia/mediawiki/blob/REL1_34/includes/cache/MessageCache.php#L887

[1] Some linters will reject message lists with just one item, e.g.: mediawiki/msg-doc doesn't accept valid docs with 1 entry.

[2] ttp://dev.w3.org/csswg/css3-writing-modes/

[3] w:Quotation_mark#Summary_table

[4] ttp://www.w3.org/QA/Tips/noClickHere

[5] ttps://github.com/wikimedia/mediawiki/blob/REL1_34/includes/cache/MessageCache.php#L887

[1]

[2]

[3]

[4]

[5]

Help:システムメッセージ

ウィキ上でのメッセージのオーバーライド

メッセージとその説明文を見つける

地域化ファイルの書式

JSON

ファイルの場所

メタデータ

規約

PHP

メッセージの使用

メッセージのソース

キャッシュ

Function backtrace

MessageCache

LocalisationCache

LCStore

新しいメッセージの追加

メッセージキーを選ぶ

ジェンダー

メッセージを作成するときにその他に注意すること

翻訳するべきではないメッセージ

既存のメッセージの除去

既存のメッセージの変更

メッセージについての説明文

国際化のヒント

メッセージのパラメーターやスイッチを適切に使用する

メッセージの再利用を避ける

「継ぎ接ぎ」メッセージの回避

互いに引用するメッセージ

Write messages in natural language

特定のプロジェクトに特化した用語やテンプレートを使用しない

文章で時刻を日付から分離する

メッセージで {{SITENAME}} を避ける

Avoid references to visual layout and positions

画面の色の参照の回避

メッセージ内の翻訳されないHTMLマークアップの回避

翻訳済みのメッセージは想定外の長さに達することが多い!

異なるものや概念を示すために非常に近い、類似または同一の単語を使用するのを避ける

Basic words may have unforeseen connotations, or not exist at all

必要なときに ‎<code>、‎<var>、および ‎<kbd> タグを使用する

記号、コロン、括弧などはメッセージの一部

Do not expect symbols and punctuation to survive translation

終止符(句点)の使用

アンカーにリンクする

リンクのウィキテキスト

意味のあるリンクアンカーを使用する

専門用語やスラングを避ける

空白や改行に気を付ける

標準的な大文字化の使用

強調

関連項目

注記

メッセージで `{{SITENAME}}` を避ける

必要なときに `‎<code>`、`‎<var>`、および `‎<kbd>` タグを使用する