"alE13" is likely a release group tag or a specific encoding identifier used by the uploader to distinguish this version (such as resolution or source type).
Identifiers like "alE13" often function as versioning or collection codes to help users distinguish between different edits or qualities of the same title.
When documenting or identifying files in an archive, standard file naming conventions prioritize descriptive, unique, and human-readable names .
For further analysis, do you have the in this set or File-Naming - State Archives of North Carolina