Upper gastrointestinal series tract in addition to barium, and this procedure is called double-contrast imaging. In this case the gas is referred to as the negative contrast medium. Traditionally the images produced with barium contrast are made with plain-film radiography, but computed tomography is also used in combination with barium contrast, in which case the procedure is called CT enterography. Various types of barium X-ray examinations are used to examine different parts of the gastrointestinal tract. These include barium swallow, barium meal, barium follow-through, and barium enema. The barium swallow, barium meal, and barium follow-through are together also called an upper gastrointestinal series
Colon (punctuation) languages like Haskell use a double colon (::) to indicate type instead. A colon is also sometimes used to indicate a tensor contraction involving two indices, and a double colon (::) for a contraction over four indices. Additional colon-related symbols for math are encoding in Unicode: In computing, the colon character is represented by ASCII code 58, (HTML :) and Unicode . Several compatibility forms for Chinese and Japanese typography are also encoded: In Hebrew: In the Budu language of the Democratic Republic of the Congo: In Microsoft Windows filenames, the colon is reserved for use in alternate data streams.