LibAnswers: MLA FAQs

The 9th edition MLA Handbook lays out a template of core elements for citing anything(105):

• Author.
• Title of Source.
• Title of Container,
• Contributor,
• Version,
• Number,
• Publisher,
• Publication Date,
• Location. 

If any element is unknown, like any other citation, just provide as much known information as possible.

You can create a shortened title for the sign based off of the written information on the sign.

If author is unknown, the publisher can be whoever commissioned the sign (a city traffic sign can be attributed to the Department of Transportation, for example). 

The location can be wherever you saw the sign.

If there is no date of creation, then you can use date of viewing as a supplemental element for the end of your works cited entry("How do I cite a sign?").

An example is provided here at the MLA Style blog: 

https://style.mla.org/how-do-i-cite-a-sign/

Works Cited

MLA Handbook. 9th ed., Modern Language Association of America, 2021.

"How do I cite a sign?" MLA Style Center, Modern Language Association of America, 21 Nov. 2017.