The idea of automatic generation of data entry forms based on data relational models is a common and known idea that has been discussed day by day more than before according to the popularity of agile methods in software development accompanying development of programming tools. One of the requirements of the automation methods, whether in commercial products or the relevant research projects, could be the concept of metadata as a mediator between database and data entry forms. The metadata usually includes some schemas and constraints of target database, which could be used as a model for automatic generation of data entry forms. However, the most metadata models proposed in relevant researches have simple and undetailed structure. In other words, only the initial requirements of data entry are included in their contents. In this study, the main objective is to emphasize structure of metadata to discuss its enrichment methods to cover more requirements of data entry. In this regard, some parts of a metadata model are also presented for objectification of the ideas.