Business milestones are usually useless in the description of standard forecasts as they are not developed by the designer team but supplied by external organizations (for example NAF is defined by the NATO and HTML is defined by the W3C). So, even though milestones can still be defined in standard master plans, it is recommended that you only have a few of them representing the very big steps in the standard evolution and that you set the start and end dates on the periods to match the different states of the standard.