Feature summary (what you would like to be able to do and where):
After switching to Vega 5, there will be a lot of graphs that are written in the old Vega 2 syntax. Over time, we will need to completely abandon it and therefore need a category to work with, as we did with Vega 1.
Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
If I want to fix the syntax in graphs, I need to know where to find them.
Benefits (why should this be implemented?):
Simplification of work.