5. The system as recited in claim 1 , wherein one or more related products are presented to the user in different categories based at least partly on the explicit associative relationships between the second product and the one or more related products.
1. A system comprising: one or more processors; memory; a classification module maintained in the memory and executable by the one or more processors to maintain a taxonomy for a catalog of products; an explicit associative relationships module maintained in the memory and executable by the one or more processors to determine a plurality of explicit associative relationships, wherein the plurality of explicit associative relationships include words or phrases that define a plurality of different types of relationships between products included in the catalog of products, the plurality of different types of relationships including at least one of: an optional accessory relationship that indicates that a first product is both suggested for use with a second product and not necessary for to using the second product, a necessary accessory relationship that indicates that the first product is necessary for using the second product, or a consumable accessory relationship that indicates that the first product is consumed during use of the first product in conjunction with the second product; a relationships assignment module maintained in the memory and executable by the one or more processors to assign the plurality of explicit associative relationships to one or more pairings of the products; a relationships parsing module maintained in the memory and executable by the one or more processors to: determine that a user has selected the second product; and parse the explicit associative relationships assigned to the second product to identify that the first product is related to the second product; and an item recommendation module maintained in the memory and executable by the one or more processors to recommend the first product to the user and to explain a nature of at least one of the optional accessory relationship, the necessary accessory relationship, or the consumable accessory relationship assigned to the second product with respect to the first product.