You create a SharePoint site collection for a law firm. You create the following objects in the site collection. A user searches for a legal case. The search results must contain only current cases…

Cases is the name of a list or library in the site collection, not a managed property, so it cannot be used directly in search result type conditions.

SharePoint search result types are built on managed properties - indexed, queryable properties that are mapped from crawled properties in the search schema. The 'MP' prefix in MPCaseID is a naming convention indicating it is a managed property, making it the appropriate object to reference when configuring a result type condition that filters for current cases. Raw column names and crawled properties cannot be used directly in result type definitions.

case refers to a content type name rather than a managed property, and result type conditions require managed properties defined in the search schema.

ows_CaseID is a crawled property (the ows_ prefix denotes a raw SharePoint list column value discovered during crawl), and crawled properties must first be mapped to a managed property before they can be used in result type rules.

CaseID is the site column name and is not itself a managed property - it must be mapped through the search schema to a managed property before it can be referenced in result type conditions.