In general, terms are represented in the singular rather than the plural.
- | breast procedure | instead of | Breasts procedure |
- | Disorder of lung | instead of | Disorder of lungs |
- | Adrenal imaging | instead of | Adrenals imaging |
Organizational nodes, also called "grouper" concepts, may have a synonym that is plural. There is a special term type for these plurals.
- | Procedures for splenic lesions |
- | Diseases of mitral and aortic valves |
- Fully-specified names should not be given in plural form unless the concept necessarily involves multiples. Unintended plurals might mislead data analysts into incorrectly inferring there were multiples when there was in fact only one.
- An unintended plural is the use of a plural in a name for a code that might be attached to a case where there is only one of the entity being coded.
- For example, consider "trochlear lesion" versus "trochlear lesions": Since users will want to use this code to refer to a single trochlear lesion, the singular form of "lesion" is correct, and the plural form would be incorrect.
- As another example, consider "multiple cranial nerve palsies": In this case, the word "multiple" indicates that there can never be just one, so a plural form of "palsies" is correct, and the singular would be incorrect.
Note: These rules apply to the FSN, and should apply to preferred display names to be used in coding. Exceptions to these rules might be allowed for special synonyms used for navigation, where the broad category is more naturally named using a plural. However, it would be advisable to keep track of these exceptions in a separate subset or using a special term type so that they can be excluded when the singular/plural distinction is important for coding.