Model-Based Definition > Geometric Dimensioning and Tolerancing Advisor > Dialog Help > Change in Tolerancing Standard
  
Change in Tolerancing Standard
There are significant differences in the rules for ASME and ISO tolerancing standards. This message indicates that there is GD&T Advisor data that was created based on a tolerancing standard other than the current tolerancing standard. In this situation, it is best to delete all GD&T Advisor data and start over in order to ensure that all GD&T is created in accordance with the desired tolerancing standard.