Section 6 of the 9303 part 3 document specifies transliteration of letters outside the A–Z range. It recommends that diacritical marks on Latin letters A-Z are simply omitted (ç → C, ð → D, ê → E, ñ → N etc.), but it allows the following transliterations:

• å → AA
• ä → AE
• ð → DH
• ij (Dutch letter; capital form: IJ, the J as part of the ligature being capitalized, too)→ IJ
• ö → OE
• ü → UE (German) or UXX (Spanish; not used in reality)
• ñ → NXX (not used in reality)

The following transliterations are mandatory:

• æ → AE
• ø, œ → OE
• ß → SS
• þ → TH

In Germany, Austria, Switzerland, Hungary and Scandinavia it is standard to use the Å→AA, Ä or Æ→AE, Ö or Ø→OE, Ü→UE, and ß→SS mappings, so Müller becomes MUELLER, Gößmann becomes GOESSMANN, and Hämäläinen becomes HAEMAELAEINEN. ð, ñ and ü occur in Iceland and Spain, but they write them as D, N and U.

Austrian passports may (but do not always) contain a trilingual (in German, English, and French) explanation of the German umlauts and ß, e.g. 'ß' entspricht / is equal to / correspond à 'SS'.