What is MIME type "application/pics-rules"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

application/pics-rules is a MIME type for files that define content filtering rules. These rules work with the PICS system (Platform for Internet Content Selection).

They help filtering programs decide which online content is acceptable. Filtering software, parental control tools, and network safeguards use these files to enforce guidelines automatically.

Files using this MIME type carry machine-readable instructions. For example, a file with the PRF extension may contain rating criteria that a browser or security tool checks before displaying content.

Main use case: Automate the filtering of web content based on predefined rules.
Additional uses:
- Support parental control systems.
- Help schools and libraries block inappropriate material.
- Assist corporate networks in managing employee access.
Key fact: The rules are machine-readable, making content evaluation fast and systematic.

For more technical details, see the PICS specification.

Associated file extensions

.prf

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: application/pics-rules

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="application/pics-rules">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');
    
    http.createServer((req, res) => {
      res.setHeader('Content-Type', 'application/pics-rules');
      res.end('Content here');
    }).listen(3000);

Associated file extensions

.prf

FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.