The Metadata Evolution for NASA Data Systems (MENDS) Project recommended that the ISO Metadata Standards be used for ESDIS data and products. Adopting a new standard is an iterative process of collecting requirements and testing the candidate standard to determine how the requirements “fit”. Requirements from future missions, science teams, current metadata standards, data centers and users are being actively considered as we evaluate the fit of the ISO standards. Translations from DIF and ECHO metadata to ISO are important input to understanding and evaluating how discovery requirements fit into ISO. Developing these translations has resulted in identifying groups of elements that 1) fit well, 2) sort of fit, and 3) may not fit. Many of the elements that may not fit are Additional Attributes that are also outside of the ECHO and DIF standards. The first step in fitting these in is classifying them by function. Possible extensions and changes to the standard will be developed to address the elements that do not currently fit.