Historically, regulative meant simply obeying direct instructions, whereas normative meant not just the requirements of the regulative principle, but also replicating patterns established by the scriptures.
The normative principle teaches that whatever is not prohibited in Scripture is permitted in worship, as long as it is agreeable to the peace and unity of the Church.
[1] In short, there must be agreement with the general practice of the Church and no prohibition in Scripture for whatever is done in worship.
The normative principle is often contrasted with the regulative principle of worship, which teaches that only those practices or elements specifically commanded or modelled in Scripture are to be permitted in worship services.
An example of the difference between these two principles of worship (normative and regulative) can be illustrated by the example of announcing notices in church (i.e. news, upcoming events, and other information).