In the context of multi-part compressed files, "complete paper covering" is not a standard technical term. It is likely a mistranslation or a request for:

: These "parity" files are used to repair or reconstruct missing segments (like your part4.rar ) if they are damaged or deleted.

If you are trying to fix a "missing volume" error while extracting:

: To extract the full video, you must have all numbered parts (part1, part2, part3, etc.) in the same folder. If you are missing part 4, you generally need to re-download that specific file from the original source where you found the others.

: Go back to the website or folder where you obtained parts 1-3.