Including file type information directly in the file name, despite the presence of the file extension (like .docx, .jpg, .pdf), means adding descriptive words like "report", "image", or "invoice" into the name itself. The file extension is a technical suffix that directly tells operating systems and applications what type of file it is and how to open it. While adding type information to the name might seem helpful, it often becomes redundant because the extension already reliably provides this information to both computers and users familiar with common extensions.

For instance, a graphic design team collaborating on assets might name a logo file CompanyLogo_AI.ai (redundantly including "AI"), whereas CompanyLogo_Final.ai adds useful version context instead. Similarly, a researcher managing data archives might use names like Experiment1_SummaryData.csv to combine project context and data type, even though ".csv" already identifies it as spreadsheet data.

Advantages include potential immediate clarity for users unfamiliar with extensions or in situations where extensions are hidden. However, key limitations are redundancy and verbosity, unnecessarily increasing name length without adding unique value in most technical environments. This practice also complicates automated sorting and searching based solely on the standardized extension, as filenames become cluttered. Consequently, focusing on including other descriptive keywords or versioning in the name while relying on the extension for type is generally considered better practice.