Which unique identifiers are recommended for limiting message search results?

Utilizing MRN (Medical Record Number), CSN (Case or Serial Number), or order ID as unique identifiers for limiting message search results is highly effective due to their precision in linking messages to specific patients, cases, or orders within the healthcare system. MRN and CSN are unique to each individual patient and case, ensuring that the search results returned pertain exactly to the intended subject. This reduces ambiguity and increases the efficiency of locating relevant messages in a system that could contain numerous individuals' records.

In contrast, other identifiers like patient name may lead to multiple results if there are common names among patients, while date and time could result in a broader search scope that includes several messages around the same time, thus reducing specificity. Location of the user is more contextual and does not directly correlate with the content or subject of a message, making it less suitable for narrowing search results effectively. Therefore, MRN, CSN, or order ID are the most reliable identifiers for refining search results in a structured and efficient manner.