Based on the filename , this appears to be a reference to a Capture The Flag (CTF) or digital forensics challenge. In these contexts, "write-ups" explain how to extract hidden data or solve puzzles within the file.

Used to browse through different color planes of an image to find hidden text or QR codes.

Often, these files are password-protected. Common steps include: Checking the challenge description for clues.

Challenges named "cats 1," "cats 2," and "cats 3" often involve layers. You might find a password in the metadata of "cat1.jpg" that unlocks a hidden zip file inside "cat2.png," eventually leading to the final flag in "cats 3.rar." Alternative Context: Australian Military Slang