In certain cases compound words and set phrases may be contracted into single characters. Some of these can be considered logograms, where characters represent whole words rather than syllable-morphemes, though these are generally instead considered ligatures or abbreviations (similar to scribal abbreviations, such as & for "et"), and as non-standard. These do see use, particularly in handwriting or decoration, but also in some cases in print. In Chinese, these ligatures are called héwén (合文), héshū (合書) or hétǐzì (合体字), and in the special case of combining two characters, these are known as "two-syllable Chinese characters" (双音节汉字, 雙音節漢字).

What may be contracted into single characters?