What is MIME type "application/lotus123"?

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

The MIME type application/lotus123 identifies files created by the Lotus 1-2-3 spreadsheet program. It tells software that the file contains data arranged in rows and columns, with built-in formulas and formatting.

Files using this MIME type were common for business spreadsheets. They helped users manage, calculate, and analyze numerical data. Today, these files are mostly seen in legacy data collections and when converting older documents. For example, file types like WK4 (Lotus 1-2-3 Worksheet 4-5) and WK3 (Lotus 1-2-3 Worksheet 3.0) use this MIME type.

Data Organization: Supports cell-based storage for numbers, text, and formulas.
Legacy Support: Maintains compatibility with older business and financial records.
Interoperability: Some modern applications can import these files to convert or edit the data.

This MIME type helps web servers and applications correctly process the file content. For more on MIME types, visit MIME on Wikipedia.

Associated file extensions

.wk4, .wk3

Usage Examples

HTTP Header

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


    Content-Type: application/lotus123

HTML

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


    <a href="file.dat" type="application/lotus123">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/lotus123');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.wk4, .wk3

FAQs

What software opens files with the MIME type application/lotus123?

Since Lotus 1-2-3 is discontinued, you typically need modern spreadsheet software that supports legacy imports to open these files. LibreOffice Calc and Corel Quattro Pro can often open .wk4 and .wk3 files. Older versions of Microsoft Excel may also support importing this data.

How do I configure Apache to serve Lotus 1-2-3 files correctly?

To ensure your Apache server sends the correct headers for Lotus files, add the AddType directive to your configuration or .htaccess file. Use the line AddType application/lotus123 .wk4 .wk3 to associate the MIME type with the specific file extensions.

Why does my browser download the file instead of displaying it?

Web browsers like Chrome, Firefox, and Edge do not have built-in engines to render legacy Lotus 1-2-3 spreadsheets. Because the browser cannot display application/lotus123 content natively, it defaults to downloading the file so you can open it with a desktop application.

Are application/lotus123 and application/vnd.lotus-1-2-3 the same?

They refer to the same file format, but application/vnd.lotus-1-2-3 is the official vendor-specific MIME type registered with IANA. However, application/lotus123 was widely used in older server configurations and documentation. You may encounter either when dealing with legacy archives.

Can I convert application/lotus123 files to Excel formats?

Yes, you can usually convert these files by opening them in compatible software like LibreOffice and using the "Save As" function to select .xlsx or .csv. There are also online file conversion tools that accept this MIME type and output modern spreadsheet formats.

Is it safe to open application/lotus123 files?

Legacy spreadsheet files can contain macros (scripts) that were historically used to spread viruses. While modern software often blocks these by default, you should always scan files from untrusted sources before opening them, even if the file format is decades old.

How do I add support for this MIME type in Nginx?

In Nginx, open your mime.types file (usually located in /etc/nginx/) and add the entry inside the types { } block. Add the line application/lotus123 wk4 wk3; and reload the server to apply the changes.

General 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.