Start with the card number printed on the card. A code such as OP05-119 points to a specific card identity in a release. Search that code in Umi to find its catalog entries.
Check the exact printing
The number alone may not settle the version. Regular, parallel, alternate artwork, promo, and reprint editions can share a number. Compare the artwork, rarity, language, and release information before selecting a printing.
Keep language separate
English and Japanese cards may share a number but are different physical printings. Umi lists them separately so a collection records what you actually own.
When the scanner is unsure
Use manual number entry or review the candidate printings. Confirming the card yourself is especially useful for foil cards, sleeves, and artwork variants.