1. A method for generating a small update package adapted for allowing update of an old version of content to a new version of content, comprising: (i) obtaining a conversion element associated with said old version and new version and a delta between said old and new versions, said conversion element and said delta form part of an update package; (ii) generating a small delta that includes modified data entries; the generation of said modified data entries comprising: a) applying said conversion element to items of said old version, said items corresponding to data entries in said delta, giving rise to converted old items; and b) generating said modified data entries based at least on said data entries and said converted old items; (iii) generating said small update package by associating said conversion element with said small delta.