Patent ID: 8250058

Claim:
A computer system that stores descriptions of multiple different types of marketplace items as a collection of parameter-value pairs, comprising: at least one server comprising a memory configured to store: a table having a plurality of rows and columns, wherein values for at least a first item and a second item of the items are stored in cells of a first row and a second row, respectively, of the plurality of the rows; a first item class key stored in the first row associated with the first item, wherein the first item class key represents a first item class and provides information used to decipher differential mappings of a plurality of the columns to a first plurality of parameters for the first row; and a second item class key different from the first item class key stored in the second row associated with the second item, wherein the second item class key represents a second item class different from the first item class, and wherein the second item class key provides information used to decipher differential mappings of the plurality of the columns to a second plurality of parameters for the second row that is different from the first plurality of parameters and where the mappings of the second row are different from the mappings of the first row; a first display interface configured to display to a human end-user identifiers for at least two of the parameters; and a second display interface configured to display to the user at least some values associated in the system with at least one of the first and second pluralities of parameters.