Final answer:
The convention used in ICD-10 for unspecified conditions is NOS, meaning Not Otherwise Specified. It is used when there is no specific code for a patient's condition due to inadequate information or an unclear diagnosis.
Step-by-step explanation:
When the ICD-10 does not provide a code that is specific enough for a patient's condition, the convention used is NOS, which stands for Not Otherwise Specified. This indicates that there is no more specific code available for the condition. In coding, using 'NOS' is a common practice when the medical record provides insufficient information to pinpoint a more precise diagnosis, or when the diagnostic statement is unclear.
It is different from 'NEC', which stands for Not Elsewhere Classifiable, used when a specific condition does not have its own code in the ICD-10 but can be identified as being different from other conditions that are listed. On the other hand, brackets [[]] are typically used in the tabular list to enclose synonyms, alternate wording, or explanatory phrases, while parentheses (()) are used to enclose supplementary words that may be present or absent in the statement of a disease or procedure without affecting the code number.