Rules for the use of the IJ in public records

Spoken Dutch has a sound that is written as either "ij" (lange IJ) or as "ei" (korte IJ). The way it is spelled indicates a difference of meaning (lijden vs. leiden, that is "to suffer" or "to lead"). By many people the IJ is perceived as a single vowel (which is phonetically not correct). The special position the IJ occupies has led to special rules unanimously adopted in Dutch texts and writing usage. In automated systems these rules have to be respected as much as possible, even if these appear to be unique in the world.

Some international standards for character coding consider the "IJ" a ligature and code it as a single letter (ISO/IEC 6937 and ISO/IEC 10646). Others (ISO/IEC 646, ISO/IEC 8859) only present the possibility of coding the IJ as two separate letters (digraph). In order to avoid unnecessary confusion between equally displayed, but differently coded words or names in the same record or file, and to promote unambiguous identification, fixed rules are required.


At including a personal name, or a geographical indication, into a file, the IJ shall be coded as TWO separate letters, I and J.


Though the rule classifies the IJ as a digraph, it does not invalidate the following rules that have become adopted in common usage.

  1. The IJ is never hyphenated between I and J.
  2. For indicating a stressed syllable an acute accent is placed on the i, not on the j.
  3. If an I and a J occur at the beginning of a word that has to start with a capital letter, then both shall be written as a capital letter.
  4. At alphabetic ordering one may select one of the following rules: 
    a. I and J are treated as two independent letters, and are thus placed between Ii and Ik, if occurring in succession. (lexicons)
    b. IJ is considered the equivalent of the Y; at comparing words being identical but for this, IJ precedes Y (cf. IJpma, Ypma). (lists of names and places, in telephone directories)
  5. At abbreviation of a first name of a person both I and J are kept. (IJsbrand Eises Ypma --> IJ. E. Ypma)
  6. In words written vertically, like occurring in shop signs and in crossword puzzles, the IJ is placed horizontally, as if it were a single letter.
  7. There are cases where the succession of I and J does not mean a IJ, and applying of automated rules would produce incorrect results. This can be avoided by inserting a hyphen in between (plooi-jurk, Mooi-Japiksteeg) or by including the word into a list of exceptions (bijouteriekastje).

  8. The following cases are furthermore not considered a violation of the rule.

  9. As the result of formatting of a text for printing, I and J may be put as close to each other as is desirable from a typographic point of view, even if this involves "kerning".
  10. Use of a single key for the IJ on a keyboard is allowed if this is applied consistently and no coding is implied.
  11. Temporary coding of the IJ as if being a single symbol during text processing is allowable.