Special operations are a type of Blitline job that doesn't follow the standard file flow. These often include things that aren't image operations and happen outside the normal flow. Some of these things include:

Vector to Vector transfomations
Video Transformations
Zipping Files,
...and many more

These jobs follow a similar format to regular Blitline jobs, but they often have a node called "pre_processing* (which we know is not the best term) but it implies it happens before generic Blitline functions happen.