Optical Recognition of Handwritten Digits: E. Alpaydin, C. Kaynak. UCI Machine Learning Repository.
DOI: 10.24432/C50P49
Source: https://archive.ics.uci.edu/dataset/80/optical+recognition+of+handwritten+digits
Dataset licensed CC BY 4.0: https://creativecommons.org/licenses/by/4.0/
Modification: teaching-only re-splits/reformatted CSV with explicit label coding; not official evaluation protocol.
Public benchmark labels are obtainable from the source: not a secret examination dataset.
