U+0133 Latin Small Ligature Ij

The Wikipedia has the following information about this codepoint:

IJ (lowercase ij; Dutch pronunciation: [ɛi] ; also encountered as Unicode compatibility characters IJ and ij) is a digraph of the letters i and j. Occurring in the Dutch language, it is sometimes considered a ligature, or a letter in itself. In most fonts that have a separate character for ij, the two composing parts are not connected but are separate glyphs, which are sometimes slightly kerned.

An ij in written Dutch usually represents the diphthong [ɛi]. In standard Dutch and most Dutch dialects, there are two possible spellings for the diphthong [ɛi]: ij and ei. That causes confusion for school children, who need to learn which words to write with ei and which with ij. To distinguish between the two, the ij is referred to as the lange ij ("long ij"), the ei as korte ei ("short ei") or simply E – I. In certain Dutch dialects (notably West Flemish and Zeelandic) and the Dutch Low Saxon dialects of Low German, a difference in the pronunciation of ei and ij is maintained. Whether it is pronounced identically to ei or not, the pronunciation of ij is often perceived as being difficult by people who do not have either sound in their native language.

The ij originally represented a 'long i'. It used to be written as ii, as in Finnish and Estonian, but for orthographic purposes, the second i was eventually elongated, which is a reason why it is called lange ij. This can still be seen in the pronunciation of some words like bijzonder (bi.zɔn.dər), and the etymology of some words in the Dutch form of several foreign placenames: Berlin and Paris are spelled Berlijn and Parijs. Nowadays, the pronunciation mostly follows the spelling, and they are pronounced with [ɛi]. The ij is distinct from the letter y. Particularly when writing capitals, Y used to be common instead of IJ in the past. That practice has long been deprecated, but the standard Dutch pronunciation of the letter Y is still ij when the alphabet is read. In scientific disciplines such as mathematics and physics, the symbol y is usually pronounced ij.

To distinguish the Y from IJ in common speech, however, Y is often called Griekse ij (meaning "Greek Y"), a literal translation of i-grec (from French, with the stress on grec: [iˈɡrɛk]) or alternatively called Ypsilon. In modern Dutch, the letter Y occurs only in loanwords, proper nouns, or when deliberately spelled as Early Modern Dutch. The spelling of Afrikaans (a daughter language of early modern Dutch) has evolved in the exact opposite direction and IJ has been completely replaced by Y.

However, the ancient use of Y in Dutch has survived in some personal names, particularly that of Dutch immigrants in the United States, Canada, Australia and New Zealand where as a result of anglicization, the IJ became a Y. For example, the surname Spijker was often changed into Spyker and Snijder into Snyder.