This is the compression codec. It’s the industry standard for maintaining decent visual quality while keeping the file size small.
This tells us the source was a high-definition digital stream, which was then "ripped" or encoded down.
Since this specific ID appears to be associated with , here is a blog post template you can use: Technical Breakdown: Understanding the IDL13SKMHD Release Published October 22, 2022
Because this file uses the container, it is highly versatile. MKVs allow for multiple subtitle tracks and audio channels to be baked into a single file. For a 480p HDRip, you can expect a file size that is very "storage-friendly," making it a popular choice for users with limited bandwidth or older hardware.