The precomposed characters are included in the character set to aid computer systems with incomplete Unicode support, where decomposed equivalent characters may render incorrectly.
Similarly, ligatures are precompositions of their constituent letters or graphemes.
For example, the two strings
OpenType has the ccmp "feature tag" to define glyphs that are compositions or decompositions involving combining characters.
In theory, most Chinese characters as encoded by Han unification and similar schemes could be treated as precomposed characters, since they can be reduced (decomposed) to their constituent strokes and ideograph descriptions, though Unicode does not take this approach that would certainly be on the cutting edge of text storage and layout. Such an approach could potentially reduce the number of characters in the character set from tens of thousands to just a few hundred.
US Patent Issued to NEC on July 19 for "Data Management System, Data Registration Device, Data Retrieval Device, Data Management Method and Program" (Japanese Inventor)
Jul 31, 2011; ALEXANDRIA, Va., July 31 -- United States Patent no. 7,984,077, issued on July 19, was assigned to NEC Corp. (Tokyo). "Data...