It's written ideographically.    From Wordnet, Princeton University. 

Babylonian-Assyrian proper names -- we have variant readings, the same name being written phonetically in whole or part in one instance and ideographically in another.    From Wordnik.com.  [Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 1 "Austria, Lower" to "Bacon"] Reference

The proper names of the numerous business documents of the Khammurabi period, when phonetic writing was the fashion, have been of special value in resolving doubts as to the correct reading of names written ideographically.    From Wordnik.com.  [Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 1 "Austria, Lower" to "Bacon"] Reference

A second name of the city, which perhaps originally denoted a separate village or quarter, was Su-anna, and in later inscriptions it is often represented ideographically by E-ki, the pronunciation and meaning of which are uncertain.    From Wordnik.com.  [Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 1 "Austria, Lower" to "Bacon"] Reference

Every character had more than one phonetic value; many of them, indeed, had several, while they could also be used ideographically to express objects and ideas.    From Wordnik.com.  [Babylonians and Assyrians, Life and Customs] Reference

So fond were the Egyptians of their pictorial symbols used ideographically that they clung to them persistently throughout the entire period of Egyptian history.    From Wordnik.com.  [A History of Science: in Five Volumes. Volume I: The Beginnings of Science] Reference

Plutarch says it means, but his method of reading them together is wrong, and it proves that he did not understand that hieroglyphics were used alphabetically as well as ideographically.    From Wordnik.com.  [Legends of the Gods The Egyptian Texts, edited with Translations] Reference

But by degrees, as respect for Chinese literature developed, it became a learned accomplishment to pronounce Japanese words after the Chinese manner, and the habit ultimately acquired such a vogue that the language of men -- who wrote and spoke ideographically -- grew to be different from the language of women -- who wrote and spoke phonetically.    From Wordnik.com.  [A History of the Japanese People From the Earliest Times to the End of the Meiji Era] Reference

"the City," which it continued to bear when written ideographically.    From Wordnik.com.  [Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 1 "Austria, Lower" to "Bacon"] Reference

For, unlike all other Semitic dialects, Assyrian is written not alphabetically, but either syllabically or ideographically, which means that Assyrian characters represent not consonants, but syllables, open or closed, simple or compound, and ideas or words, such as ka, bar, ilu, zikara, etc.    From Wordnik.com.  [The Catholic Encyclopedia, Volume 2: Assizes-Browne] Reference

These same characters may also have both a syllabic and an ideographic value, nearly always more than one syllabic value and as many as five or six; so that a sign like the following (= |) may be read syllabically as ud, ut, u, tu, tam, bir, par, pir, lah, lih, hish, and his; ideographically as umu, "day"; pisu "white"; Shamash, the Sungod; etc.    From Wordnik.com.  [The Catholic Encyclopedia, Volume 2: Assizes-Browne] Reference