I believe you are referring to the app store guidelines. The article mentions the android market place.
In every product, there core features, then there are minor / convenience features. Let's say you have a "search" feature. That is a core part of the app / product / service. Some features that you can probably put off are: "advanced search", "refinement search", or even "sorting results". All of these are convenient, but you may want to have the app in store without these features.