| Diacritics dropped | Remove the mark from ł, ś, ż and the word — or the name on a certificate — changes. Software and careless typing strip them silently. | Diacritics are preserved throughout and names matched character-by-character to the passport. |
| Name declension (seven cases) | Polish names appear in different case forms in running text. Lifted in an oblique case, a name is recorded wrongly. | Names are restored to their base form and matched to the ID, so records are consistent. |
| Gendered surnames -ski / -ska | Adjectival surnames change by gender. Apply the wrong ending and the name no longer matches the passport holder. | The correct gendered form is used and matched exactly to the passport. |
| Verbal aspect perfective/imperfective | Polish grammaticalises aspect. The wrong aspect changes whether an act is completed or ongoing — decisive in a contract or ruling. | The correct aspect is chosen, so completion and duration are rendered accurately. |
| False friends DE–PL | Words that look German but mean something else slip through. In an official text a false friend is a real error. | Terminology is checked by a native specialist, so false friends are caught, not carried over. |
| No articles, different sentence logic | Polish has no articles and orders information differently. Mapped 1:1 from German, sentences read stiff or ambiguous. | Text is rewritten in natural Polish structure, not word-mapped from German. |
| German place-name exonyms | German and Polish use different names for the same places (e.g. exonyms on old documents). Mixed, a place is misidentified. | Place names are set in the form valid for the target and document, not blended. |