Generally: If a parameter has multiple values, such as more than one librettist (as in example 2 below), more than one basis, use {{flatlist}} or {{plainlist}}.

Simple version

{{Infobox opera
| name              = <!-- default is page name -->
| genre             = <!-- default is [[Opera]] -->
| composer          = 
| image             = 
| caption           = 
| librettist        = 
| language          = 
| based_on          = <!-- {{Based on|work|author}} -->
| premiere_date     = <!-- {{Start date|YYYY|MM|DD|df=y}} or {{Start-date|<any unambiguous date format>}} -->
| premiere_location = 
}}

Long version

{{Infobox opera
| name              = 
| italic title      = <!-- yes / no; defaults to yes -->
| genre             = 
| composer          = 
| image             = 
| image_upright     = 
| alt               = 
| caption           = 
| description       = 
| native_name       = 
| native_name_lang  = <!-- ISO 639-1 code e.g. "fr" for French. If more than one, use {{lang}} instead -->
| translated_name   = 
| other_name        = 
| librettist        = 
| language          = 
| based_on          = <!-- {{Based on|work|author}} -->
| premiere_date     = <!-- {{Start date|YYYY|MM|DD|df=y}} or {{Start-date|<any unambiguous date format>}} -->
| premiere_location = 
| other             = <!-- {{Collapsible list|title=}} -->
| website           = <!-- {{URL|example.com}} -->
}}

name

Title of the opera as it appears in the article title. This will appear at the top of the infobox above the image.

italic title

Normally yes to italicise the article's title; defaults to yes

genre

This parameter shows above the image. The default is Opera. If a work is widely known as an operetta, e.g. The Merry Widow, or as a zarzuela, e.g. Doña Francisquita, these linked terms can be used instead of "Opera".

For consistency with other infoboxes on music, it can also be |type=, earlier versions may have also have |genre_header=.

composer

person/people who wrote the music

image

An illustrative image. This can be the composer (preferably close to the time of the composition), a scene from the opera, a depiction of one or more of its characters, a singer depicted in one of the opera's roles, a poster, the title page or cover of the libretto, etc. Avoid images with a large vertical dimension in relation to their width, as this can make the infobox excessively long and interfere with the page layout.

image_upright

image scaling factor; defaults to 1; see WP:THUMBSIZE

alt

alternative text for image; see WP:ALT

caption

caption for image

genre

best left unspecified, – only if needed for a referenced sub-genre stated in the article e.g. dramma giocoso. However, do not list the sub-genre if it would lead to misleading oversimplification. Sub-genre distinctions can be very blurry, and are best explicated in the article text.

description

possibility of a description, when no genre fits, but best left blank

native_name

This parameter will appear as Native title in the box. Use this field if the title of the opera article is not the native title, e.g. If the title of the article is The Marriage of Figaro, the native name would be Le nozze di Figaro. See Example 1 below.

native_name_lang

ISO 2-letter code (e.g. it for Italian) for the language of the native name, (if more than one, use {{lang}} instead). This parameter will not be visible in the box.

translated_name

This parameter will appear as Translation in the box. If the title of the opera article uses its native (non-English) name, use this to list the standard English name, if and only if, there is one, e.g. for Götterdämmerung, the translated name would be Twilight of the Gods. See Example 2 below. Do not use invented or ad hoc translations in this field. If there is no standard English name, leave it blank.

other_name

This parameter will appear as Other title in the box. Use this when the opera is known by two or more names. e.g. for Le convenienze ed inconvenienze teatrali, the other name is Viva la mamma. See Example 1 below which has a name, native name, and other name.

librettist

person/people who wrote the text. If the composer wrote the libretto, they should be listed as librettist.

language

the original language(s) in which the text was written. Do not list subsequent translations.

based_on

Use this to state the literary work or other subject on which the libretto was based (if any). Do not list a work here unless it is specifically mentioned and referenced in the article. Use {{Based on}} to do so.

premiere_date

Use {{Start date}} or {{Start-date}}.

premiere_location

Venue and/or city; will appear on the line following the premiere date.

other

This can be used for listing other operas by the same composer and their premiere dates in a collapsible list. Use {{Collapsible list}} The |title= parameter should be filled in as "Operas by X (composer's name)". See Example 3 below. This will not be necessary if the article already has a footer navbox listing the composer's operas, e.g. {{Giuseppe Verdi}}, {{Pyotr Ilyich Tchaikovsky}}, {{Antonio Vivaldi}}, etc. If the composer does not have a footer navbox, consider creating one.

website

Official website for the opera (if any). This will apply to contemporary works only. See Example 3. Use {{URL}}.

The Queen of Spades
by Pyotr Ilyich Tchaikovsky
Composer Pyotr Ilyich Tchaikovsky
Native title	Пиковая дама (Pikovaya dama)
Other title	Pique Dame
Librettist	Modest Ilyich Tchaikovsky
Language	Russian
Based on	"The Queen of Spades" by Pushkin
Premiere	19 December 1898 (1898-12-19) Mariinsky Theatre, St. Petersburg

{{Infobox opera
| name              = The Queen of Spades
| composer          = [[Pyotr Ilyich Tchaikovsky]]
| native_name       = Пиковая дама (''Pikovaya dama'')
| native_name_lang  = ru
| image             = Peter Tschaikowski.jpg
| caption           = Composer Pyotr Ilyich Tchaikovsky
| genre             =
| other_name        = {{lang|fr|Pique Dame}}
| librettist        = [[Modest Ilyich Tchaikovsky]]
| language          = Russian
| based_on          = {{tl|Based on|"[[The Queen of Spades (story)|The Queen of Spades]]"|[[Alexander Pushkin|Pushkin]]}}
| premiere_date     = {{Start date|1898|12|19|df=y}}
| premiere_location = [[Mariinsky Theatre]], [[Saint Petersburg|St. Petersburg]]
}}

Falstaff
Opera by Giuseppe Verdi
Lucien Fugère in the title role, 1894
Librettist	Arrigo Boito
Language	Italian
Based on	The Merry Wives of Windsor and scenes from Henry IV, parts 1 and 2 by Shakespeare
Premiere	9 February 1893 (1893-02-09) La Scala in Milan

{{Infobox opera
| name              = ''Falstaff''
| composer          = [[Giuseppe Verdi]]
| image             = Lucien-Fugère-as-Falstaff.jpg
| image_upright     = 0.8
| caption           = [[Lucien Fugère]] in the title role, 1894
| librettist        = [[Arrigo Boito]]
| language          = Italian
| based_on          = {{based on|''[[The Merry Wives of Windsor]]'' and scenes from ''[[Henry IV (Shakespeare play)|Henry IV]]'', parts 1 and 2|Shakespeare}}
| premiere_date     = {{Start date|1893|02|09|df=y}}
| premiere_location = {{Nowrap|[[La Scala]] in Milan}}
}}

Nixon in China
Opera by John Adams
Composer John Adams, 2008
Librettist	Alice Goodman
Language	English
Premiere	October 22, 1987 (1987-10-22) Wortham Theater Center, Houston
Website	www.earbox.com/nixon-in-china/

{{Infobox opera
| name              = Nixon in China
| composer          = [[John Adams (composer)|John Adams]]
| image             = JA-portrait-1-LW.jpg
| caption           = Composer John Adams, 2008
| librettist        = [[Alice Goodman]]
| language          = English
| premiere_date     = {{Start date|1987|10|22}}
| premiere_location = [[Wortham Theater Center]], Houston
| website           = {{URL|http://www.earbox.com/nixon-in-china/}}
}}
}}

The Demon Editor of Wikipedia
Operetta by John Smith
An example image
Native title	Il diavolo di Wikipedia
Other title	Wiki Devil
Librettist	Jane Doe
Language	Italian
Premiere	18 March 2013 (2013-03-18) Toytown
Website	example.com

{{Infobox opera
| name              = The Demon Editor of Wikipedia
| type              = [[Operetta]]
| composer          = John Smith
| native_name       = ''Il diavolo di Wikipedia''
| native_name_lang  = it
| image             = Backer Judgment (detail).JPG
| alt               = A drawing of the devil
| caption           = An example image
| other_name        = ''Wiki Devil''
| librettist        = Jane Doe
| language          = Italian
| premiere_date     = {{Start date|2013|03|18|df=y}}
| premiere_location = Toytown
| website           = {{URL|example.com}}
}}