1. A server comprising: a memory; and a processor coupled to the memory, the processor programmed to: access a plurality of files; manage a first content property including a first name and a first expression and a second content property including the first name and a second expression; extract values from fields in individual files of the plurality of files, each of the fields expressed by the first expression or the second expression; index the individual files with the first name and one more respective extracted values; and search, when receiving a query specifying the first name and a specified value, one or more of the files that are indexed with the specified value.