14 hours ago
- Excel column labeling is not base-26; it's bijective base-26, which has a one-to-one correspondence with positive integers without leading zeros.
- Before 2007, Excel had a maximum of 256 columns (label IV); after 2007, the limit increased to 16,384 (label XFD).
- Conversion between column labels and numbers is implemented using bijective base-26 arithmetic, working for arbitrarily large integers.