Wikipedia:WikiProject Opera/Category guidelines

All opera title articles belong in:

• :Category:Operas. For further information see Non-diffusing subcategories.

Operas are further categorized minimally by:

;Composer

• :Category:Operas by composer

;Genre

• :Category:Operas by genre (which should be plural and in the original language used in standard reference books to avoid confusion). For the purposes of Wikipedia (and indeed other encyclopedias such as Grove), operettas are considered a subcategory of operas, so, for example, The Merry Widow is in :Category:Operas as well as :Category:Operettas.

;Language:

• :Category:Operas by language

;Year of premiere

• :Category:Operas by year

Other categories include Operas by setting; Operas by world premiere location; One-act operas; Unfinished operas ; Lost operas; Operas by source (for operas whose libretti are based on plays, novels, films, etc.)

In practice a single opera title article will have many category tags at the foot of the page. The order in which these appear generally starts with the most specific and ends with the most general. For example, Tosca belongs to the following categories:

:Category:Operas by Giacomo Puccini|:Category:Verismo operas|:Category:Italian-language operas|:Category:1900 operas|:Category:Operas

For typographical reasons stub tags go two line spaces after category tags

In addition to general biographical categories, opera singers are categorized by:

;Nationality:

:Category:Opera singers by nationality

;Voice

• :Category:Operatic sopranos • :Category:Operatic mezzo-sopranos • :Category:Operatic contraltos • :Category:Operatic countertenors • :Category:Operatic tenors • :Category:Operatic baritones • :Category:Operatic bass-baritones • :Category:Operatic basses

• All opera composers belong in :Category:Opera composers, although they may also appear in other composer categories as well.
• The main categories for other opera-related biographies are: :Category:Opera critics • :Category:Opera directors • :Category:Opera librettists • :Category:Opera managers

Articles which don't fall under any of the below topics can always be included (temporarily) in :Category:Opera. For further possible categories, see the full category tree for all opera-related articles.

Organizations and venues (When adding these, please check each category for the appropriate sub-category, if any)

• :Category:Opera houses
• :Category:Opera companies
• :Category:Opera festivals.
• :Category:Opera organizations for associations such as Opera Europa.

;Opera terms

• :Category:Opera terminology (note that forms of Chinese opera are listed under :Category:Performing arts not opera.)

Audio and video recordings (on 78, LP, CD, DVD etc.)

• :Category:Opera recordings.

;Publishers

• :Category:Opera publishers

;Publications

• :Category:Opera publications.

;Lists

• :Category:Opera-related lists.

To ensure that articles are listed in the correct order on their category pages, the {{tl|DEFAULTSORT}} tag needs to added at the beginning of the article's list of categories.

• The titles of articles are sorted omitting the definite or indefinite article such as "A", "The", "Le", "La", "Les", "Der", "Die", "Das", etc. For example La naissance d'Osiris requires {{DEFAULTSORT:Naissance d'Osiris}}. That means that the opera will file under N and not under L, although the actual article title ("La naissance d'Osiris") will appear in the Category listing under N.
• The default sort title should always start with a capital letter, as lower-case initial letters are filed after upper-case
• If there's a special character or accent in the title, the default sort title should not contain the special character/accent, for a similar reason. For example, if "Zéphire" isn't changed to "Zephire", it would file after "Zwerg".
• People have to be sorted in the same way, e.g. {{DEFAULTSORT:Verdi, Giuseppe}}, otherwise Verdi will appear under "G" rather than "V".