Filenames and file types

Guidelines for names

Make file and directory names lowercase, with the occasional exception for consistency, to make file searches easier and search results more useful. For example, because most Unix-style operating systems are case sensitive, they can't find a file named Impersonate-Service-Accounts.html if you search for impersonate-service-accounts.html. Linux and macOS interpret these as two distinct files.

Use hyphens, not underscores, to separate words—for example, query-data.html. Search engines interpret hyphens in file and directory names as spaces between words. Underscores are generally not recognized, meaning that their presence can negatively affect SEO.

Use only standard ASCII alphanumeric characters in file and directory names.

Don't use generic page names such as document1.html.

Exceptions for consistency

If you're adding to a directory where everything else already uses underscores, and it's not feasible to change everything to hyphens, it's okay to use underscores to stay consistent.

For example, if the directory already has lesson_1.jd, lesson_2.jd, and lesson_3.jd, it's okay to add your new file as lesson_4.jd instead of lesson-4.jd. However, in all other situations, use hyphens.

Recommended: avoiding-cliches.jd

Sometimes OK: avoiding_cliches.jd

Not recommended: avoidingcliches.jd

Not recommended: avoidingCliches.jd

Not recommended: avoiding-clichés.jd

Other exceptions

It's okay to have some inconsistency in filenames if it can't otherwise be avoided. For example, sometimes tools that generate reference documentation produce filenames based on different style requirements or based on the design and naming conventions of the product or API itself. In those cases, it's okay to make exceptions for those files.

Refer to files

The following sections discuss how to reference files.

Refer to filenames

When referring to a specific file, do the following:

• Use code font.
• Include the word file after the filename. For more information, see Grammatical treatment of code elements.
• Use the exact spelling of the filename even if it doesn't follow naming guidelines.
• If a sample of the file is included on the page, follow the code sample guidelines and precede a code sample with an introductory sentence or paragraph that includes the filename.

Recommended: In the following build.sh file, modify the default values for all parameters:

Refer to file interactions

When interacting with files and file types, don't use the file types as a verb.

Recommended: Extract a zip file.

Not recommended: Unzip a zip file.

Refer to file types

When you're discussing a file type, use the formal name of the type, not the filename extension. (The file type name is often in all caps because many file type names are acronyms or initialisms.) Do not use the filename extension to refer generically to the file type.

Recommended: a PNG file

Not recommended: a .png file

Recommended: a Bash file

Not recommended: an .sh file

The following table lists some examples of filename extensions and the corresponding file type names to use.

Extension	File type name
.adoc	AsciiDoc file
.csv	CSV file
.exe	executable file
.gif	GIF file
.img	disk image file
.ipynb	IPYNB file
.jar	JAR file
.jpg, .jpeg	JPEG file
.json	JSON file
.md	Markdown file
.pdf	PDF file
.png	PNG file
.ps	PowerShell file
.py	Python file
.sh	Bash file
.sql	SQL file
.svg	SVG file
.tar	tar file
.tf	Terraform file
.tiff	TIFF file
.txt	text file
.yaml	YAML file
.zip	zip file