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Precoordinated expressions consist of a single  concept identifier, followed optionally by any term that is associated with that  concept . While the use of a term is not mandated, it is often preferable to include preferred term s from an appropriate dialect within the expressions to improve the human-readability of the expression. For example:
73211009|diabetes mellitus|
As mentioned, the syntax does not require a term to be used with each concept identifier, so the following is also a valid  expression :
73211009

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