1. A computer-implemented method for specifying changes to a web_site, the method comprising: performing, by one or more computers: receiving a request for a first change to the web site, the web site including multiple web pages; wherein some of said web pages include item detail pages offering items for sale; wherein the first change is scheduled for release at a first specified time; wherein said web site includes a browse data structure distinct from the web pages of the web site, the browse data structure indicating a hierarchy of categories and different ones of the items for sale categorized under different categories of the hierarchy; wherein said first change is directed to a first portion of the browse data structure; prior to the first specified time for release of the first change, receiving a request for a second change to the web site, the second change scheduled for release at a second specified time different than said first specified time; wherein said second change is directed to a second portion of the browse data structure, the second portion being different than the portion of the browse data structure to which the first change is directed; wherein prior to the first specified time and the second specified time, the second portion of the browse data structure has a dependency with said first portion; wherein the dependency is specified within the browse data structure; subsequent to receiving the requests for the first and second changes, automatically determining whether said dependency between the first and second portions of the browse data structure would be broken by the release of the first change or the second change; wherein said automatically determining is performed without releasing said first and second changes on a live version of the website; and if it is determined that the release of the first change or the second change would break said dependency, providing an indication of the broken dependency.